Ah, if it was only the plucky pilot from the SNES game. Instead, he's an Eternal from Titan with the sex drive of Ron Jeremy circa 1978. The two of them hooked up during his brief time in the Avengers, but their short relationship came back to haunt her when Starfox was on trial for sexual assault. Turns out Starfox didn't have to use his sexual control powers to bed Jen, they just felt like doing it. If you can't be with the one you love, bang the Eternal you're with.
4) Luke Cage
Did they? Didn't they? The relationship was brief, but Carol Danvers more or less spilled the beans to Luke's wife over lunch one time. In the comics, there was some dating, yes, during the Heroes for Hire era, but was there sex? Ms. Marvel seems to think so. And it's a couple that is more or less unbreakable, so that had to be a fun weekend.
Cousin-humpin'! It's evil. And icky. And it happens, in the future. When the Hulk wants to reproduce, who does he go to? Someone he knows is biologically compatible and can take the strain of his highly muscled offspring. Turns out that someone is his poor cousin, Jennifer Walters, who was probably less happy about it than in the fan art above. This happened during the Old Man Logan
storyline, which is insanely nihilistic, so don't expect it to become canon, but points to Mark Millar for going there.
The lucky man-wolf who married the jade giantess (do you have any idea how hard it is to come up with different words for "She-Hulk" and "sex?"). The love affair between John Jameson and Jennifer Walters made up a good chunk of the latest She-Hulk
series, culminating with a Las Vegas wedding. And there was LOTS of sex, almost too much. It got annoying, really. Then they found out that the aforementioned Starfox was shooting them full of endorphins, and when he stopped, well, the magic was over.
Don't listen to Dan Slott, who said this was an alternate universe She-Hulk. The fans wanted it to happen and it was AWESOME. They broke the bed. They broke the floor. And Dan Slott broke our hearts when he said it didn't happen.