I'd be fine with it. Bring on the love triangle!
I have seen it. They're clearly together, but it's more than likely just a prison gay joke. Sam Rockwell is so good, so funny, and so casual about it, though, that I like to take it to mean that Justin Hammer is at least open-minded enough about it. Like, he doesn't judge and he totally could be gay or bi.
'Cos he's clearly jealous of the fact that Pepper Potts is on the cover of Forbes magazine, but with the way he goes on and on about Tony, I kind of think he has a crush on Tony, as well, and that's feeding into his jealousy of Pepper, lol. I don't remember any relationship stuff for him in the Iron Man 2 movie, not even casually checking a woman out or anything...
Anyway, I can only post one video per post, so I'm going to post the one with better quality, but chronologically speaking...
This video has a bit that happens before the joke in question (you'll have to turn your sound way up high to hear anything):
http://www.youtube.com/watch?v=dAw9Xg6czBU
Then this video has all the stuff that was in that other video, just not a little bit that happened before it: