From Alles Was Zahlt, the Eskimo Kiss Project translation:
Ben: "So your bi phase is over now?"
Deniz: "Indeed it is, yep."
And the commentary from Eskimo Kiss Project (http://awz.parakaproductions.com): "On a more serious note, Deniz Is Gay Again. Because apparently your sexual preference depends entirely upon your current sexual partner. And you must fit neatly into only one box. Bisexuality is so untidy. (Honestly, we'd be less bothered by the label if we saw the conversation behind it. And by conversation, we mean with Deniz actually talking this time.)"
Back to me: Deniz could have been saying what Roman wanted to hear, or what his educated guess was that Roman wanted to hear. And considering they're supposed to participate in the Gay Games, perhaps Deniz feels that "gay" is a good label for him. I thought "bisexual" would explain a lot as far as ret-conning the show turning Deniz more-or-less straight. Of course, Ben knows that Deniz had a relationship with Vanessa, who is Ben's half-sister. Vanessa and Ben had had a relationship before they found out they were related. In the past, Deniz had said he was gay when he was in his first relationship, with Roman; said he was confused; had relationships/sex with several women; had sex with Roman every so often in there; tried to pass himself off as straight at least once (haven't seen that many of the middle episodes of the show); and said he was confused and didn't know if he was straight, gay or bi. I imagine the show thoroughtly managed to confuse viewers, too. Judging from his actions, he's bisexual. I kind of would like to hear him say a little more about his preferences. Physically, he can go either way; emotionally, he can go either way. Not that great for having a serious relationship with a man, I don't think. Probably not so great for being in a serious relationship with a woman, either. I'm sure there are bisexual men who can be faithful to one person. It's just that you don't hear about it. Mostly you hear about them being married and sneaking off to have sex with men. I think women are more likely to be faithful with each other, but then you get all the political aspects of bisexual women stealing "woman energy" and claiming heterosexual privilege. Men are much less likely to get political about it, especially if they're just looking for sex and not a relationship.