Hugh Laurie agreed when an interviewer called Wilson "the other love of [House's] life".
In one episode, House stated (albeit sarcastically) "I'm gay", citing his closeness with Wilson and "obsession with sneakers." In another episode, House declares "I love you" when Wilson gives him more Vicodin, causing Squee in millions of Ho Yay fans.
One episode (or rather, long story arc) implies that Wilson is dating Amber because of her similarity to House. House calls him on this. Later:
Wilson: House, you're right. Why not? Why not date you? It's brilliant. We've known each other for years. We've put up with all kinds of crap from each other. And we keep coming back. We're a couple. House: Are we still speaking metaphorically?
That same scene finishes with House giving Wilson a very serious glare (indicating that he'd touched a nerve), which Wilson brushes off with a flippant, "Well, if you'd looked at me with those flashing eyes before I was involved..."
It's rather telling that, on the occasion when House was planning on crashing Cuddy's Thanksgiving dinner with the professed intention of breaking her and Lucas up, he couldn't resist asking Wilson to come with him... "as [his] date".
House once spent an inordinate amount of time rambling to his team about his and Wilson's relationship, concluding with the smugly definitive statement "And that is why he will never mate me!", prompting a long, awkward, silence and great reaction shot from the fellows. House then attempted to clarify by insisting "It's a chess term," leaving them looking thoroughly unconvinced.
Once, a gay patient of House's mistook him and Wilson for a couple, causing Wilson to stammer nervously.
In The Down Low, Wilson is frustrated because a woman he is interested in is convinced that he's dating House.
Wilson: Everyone in our building thinks we're gay. House: We're grown men over the age of thirty who moved in together. We're two tigers away from an act in Vegas.
From the episode "Birthmarks":
House: If you're coming back because you're attracted to the shine of my neediness... I'd be okay with that.
And in episode Black Hole, House forces Wilson to buy a piece of furniture that says something about him: Wilson chooses an organ that House absolutely loves. House's response is, "I like what this says about you." To elaborate, in previous episodes Wilson got mad with Cuddy for hurting House and outbid her on the loft she was trying to buy. Then he moved in with House. House spent the entire Black Hole episode pestering Wilson about furniture, going so far as to saying that if Wilson is incapable of buying furniture for himself, he's empty inside. Cue Wilson nerly driving himself crazy trying to buy furniture and failing miserably; finally, he gives in and uses an interior decorator. The only thing in the whole apartment that Wilson actually manages to choose and buy on his own is an organ, which isn't even for him, but explicitly intended for House. Implications are clear: House is the only fixed point in Wilson's life, the only thing Wilson's absolutely adamantly sure about, and he chooses to honour that. Frankly, this may be the most romantic gesture anyone on this show has made to anyone.
In Season 5, House wonders if he's hallucinating Amber, Wilson's ex, as his anima out of "some secret and very unconscious desire to get Wilson into my bedroom." There is no clue in his sleep-deprived tone to how sincere or not he's being.
From season 6, "Private Lives":
Wilson: What are you doing? House: Masturbating. I'd invite you, but people are already talking.
Season five, episode 23. House is picking a fight with Wilson, and hallucinatory!Amber cuts in with "Stop deflecting. He cares about you. You care about him. Tell him you love him." When you consider that Amber is a manifestation of House's subconscious...
In the season 7 premiere "Now What", House and Cuddy had just finished having sex, leading to this exchange which just screamsOT3.
Cuddy: Why didn't you let him in? House: You were thinking about Wilson while we were having sex? That's so cool, so was I!
The entirety of the House/Wilson subplot in season 7's Unplanned Parenthood is rife with this. For the purposes of this episode, Rachel Has Two Daddies. When problems occur with Rachel, what does House do? Does he tell Cuddy, the child's own mother? No; he immediately confides in Wilson and they spend the rest of the episode trying to hide it from her and take care of Rachel. Not to mention House's line that Wilson would be a "great 'mommy'".
In one episode House tells Cuddy that he doesn't want to go bowling with Wilson because his chances of sex with him are "considerably lower" than with her, implying that sex with Wilson is both possible and not unwanted.
In a season 2 episode House calls Wilson and greets him with "Hey honey, how are the kids?" (referring to his team. Which Wilson actually is keeping tabs on while House is away.)
From "Out of the Chute"
Carnell: Don't worry. You can trust me with anything. Including your food. House: (indicating Wilson) After he and I have sex, I'm going to slit his throat and then disembowel him in the bathtub.
The end of "Both Sides Now", when scenes of Chase and Cameron getting married are intercut with scenes of Wilson taking House to the psychiatric hospital. It's essentially a scene where one couple comes together and another is being torn apart.
In Season 6's episode "Brave Heart," House masturbates (either for real or he pretends to - the scene is rather ambiguous) in front of Wilson because he wants Wilson to set up a bed for him instead of making him sleep on the couch. The scene would not have been out of place in a Hilson fanfic.
In Season 8, Episode 2, House spends the entire episode trying to get Wilson back. He tries a risky revival method on the lungs for Wilson. He misses the sound of his voice. They have a song - and it's "My Heart Will Go On." House likes Wilson, he has fun with Wilson. He finds a vegetarian restaraunt for him. They go to dinner. House is willing to get hurt for their friendship. It's basically Ho Yay : The Episode.
House: I like you. I have fun with you. And, if you can honestly say that you don’t like me, you don’t have fun with me, I can accept that. But just do whatever you have to do to get over this. Punch me in the face, kick me in the nuts. Either/or. Both seems excessive. Wilson: The thing is, House… I don’t like you. *leaves* House: *looks broken hearted*
House now has a part of his wall moveable (he presses a button on a remote, it moves) and it opens to show Wilson's office. Aww.
In one scene House checks Wilson's temperature by touching his forehead with his.
There's a very subtle tease in No More Mr. Nice Guy. Kutner finds an old blood sample that belonged to House, and on a hunch, tests it for something that might cause neurological symptoms. The sample tests positive for syphilis. When the team gives him the news, House looks shocked for a moment, and then says "I have to talk to Wilson." The team and the audience, at this point, don't know that House planted the blood sample; because he knew that his team would eventually test it for something]. The implication is that House has to talk to Wilson to inform him that he had given him an STD.
House can sometimes act like something of a Stalker with a Crush towards Wilson, sort of. The crush part is up for debate, though. House hires a private investigator to spy on Wilson when Wilson cuts ties with House, quits his job, and moves away. The PI accuses House of wanting to see if Wilson is pining, and he's right. House is clearly upset to discover that, despite having the PI set up bugs and everything in Wilson's car and home, Wilson hasn't mentioned House at all.
Season 8's 'Better Half' gives us this gem.
House: (to Wilson) I really gotta get you laid. If I have to plough that furrow myself, so be it.
Season 8's The C-word cements it forever and ever. When Wilson finds out he has cancer, House goes on a vacation and helps him carry out an incredibly dangerous, completely nightmarish, potentially lethal and most likely illegal chemotherapy. In House's flat. House holds the bucket when Wilson's throwing up; House goes without Vicodin so he can give it to Wilson; and when Wilson's half mad with pain and screaming abuse at House, House holds his tongue. And it turned out he made a truly hilarious video of the whole terrible experience, which made Wilson laugh like he probably hasn't laughed for weeks. If that's not true love, then I don't know what is.
Wilson: If things go wrong, I just want you to know- House: If you're gonna say that you've always been secretly gay for me, (Beat) everyone always just kind of assumed it
In Post Mortem:
Wilson: I want a threesome House: Shouldn't we try a twosome first?
The penultimate episode of the show, Holding On, contains more Ho Yay than all the previous seasons put together. In addition to House almost killing a patient out of despair because Wilson's refusing further chemotherapy, we have House telling Wilson that he needs him and doesn't know what he'll do without him, Wilson asking House to tell him that he loves him and the two of them planning how they're going to spend the next five months until Wilson's death.
Wilson: Just dinner? House: Depends on how much we have to drink.
And Foreman finally expresses the beauty of House's and Wilson's friendship: they are the most lasting relationship any of them has ever had. Screw having sex: these two are in love.
And in another episode of the fourth season, we get another "I love you", said by Kutner to House when House tells the group to say what they think he wants them to say...add this to Kutner being utterly thrilled when he discovers he's House's Secret Santa, and you start to wonder why nobody else seems to be noticing these things.
Speaking of Kutner, don't forget that he took Cole out to a magic show in one episode. House even calls Cole out: "You have to leave work at 6 p.m., but you make time for man dates?" In the same episode, we also find out that Kutner has babysat Dr. Cole's son.
Don't forget House saying that he'll go with Cameron's plan because she's "barely" cuter then Chase.
Also House once said Chase has a pretty mouth.
And he keeps commenting on Chase's great hair.
Hell, Chase ranges from getting hit on by a gay patient to constant jokes by House:
House: Little girls who kiss frogs expect them to turn into you. Chase: Oh, come on, I'm not that good looking. House: Yes, you are.
(Beat) Wilson: You kind of are.
Also, in "Spin", season 2:
House: What makes a guy start drooling? (pause) Chase, were you wearing your short shorts?
The "I'm gay" quote that most people cite as House/Wilson Ho Yay actually leans more toward House/Chase, since he said it in explanation for not firing Chase because he has great hair.
There's also Season 2, Episode 8: "The Mistake", in which House insists that Chase loves him. Wilson replies that Cameron loves him, Chase merely loves his job. Despite House's "The Reason You Suck" Speech to Chase earlier in the episode, House looks genuinely hurt by the idea that his little wombat doesn't love him.
It seems everyone finds Chase ungodly attractive - House ponders aloud whether Foreman might be gay because he was unaffected by a pretty woman whom House couldn't think logically around. Wilson, without missing a beat, asks "Did he turn into an idiot around Chase?"
Just before Cameron gets married, House addresses her as "the soon-to-be-second-prettiest Dr. Chase".
In fairness, Jesse Spencer is absurdly pretty. He almost manages to beat Olivia Wilde for the title of Most Attractive Series Regular. There's a reason he's considered the series' token Mr. Fanservice.
Hugh Laurie famously said he can easily see House getting it on with Cuddy, Cameron or Wilson.
Katie Jacobs, executive producer of House, once implied this too.
From "Recession" we have the Ho Yay banter between Foreman and Taub, including being compared to Bert and Ernie (Taub's Ernie).
Season 8 starts on with some blatant House/Foreman subtext. Foreman is now in position of power, which makes the dynamic between him and House somewhat similar to that between House and Cuddy. Also, there's that time when House grabbed his ass ...
In the Vogler story arc in season 1, House is instructed to ax one of his team for budget reasons.
House: [keeping all 3] will be more cost-efficient, once i've grabbed Cameron's ass, called Foreman a spade, and Chase ... well, i'll grab his ass too
In 'Half-Wit' from season 3, Chase thinks House has terminal brain cancer and attempts to comfort him:
Chase: I'm sorry you're dying. I'm gonna hug you. Anything to say? House: Well, if you're considering grabbing my ass, don't start anything you can't finish
From the same episode, after Cameron tries to kiss House as a pretext for drawing his blood, since she also thinks House has brain cancer
House: Foreman and Chase's lips aren't getting so close, now that I know your plan.