Is it possible to negotiate masculinity within the general context of sexuality. I've talked a bit about my preference for younger guys(18-21 specifically) and I feel that I claim some degree of masculinity when I prefer younger partners I seek. If I were to be the younger in a relationship, I see myself as a feminine role. Not feminine that I see myself as trans or anything, I see myself as a feminine(subordinate) role in some regards. It's a real hard to explain in a post but I have talked this subject of masculinity and sexuality with my counselor I see bi-weekly.
Gay relationships don't have to have specific masculine and feminine roles. The idea that gay relationships do need those roles is based in the idea that gay relationships that mirror heterosexual ones will be seen as more socially acceptable. I know that resolving this your difficulties with masculinity and femininity is not as simple as just acknowledging that you don't have to fit specific roles, but when you're figuring out what works for you, remember that it's absolutely okay and possible to have both masculine and feminine aspects to the role you play in your relationship.
I don't see why the age difference should really have any bearing on the perception of which partner is more masculine. Hell, there are plenty of hot, younger guys I'd be more than happy to submit to. Lol.
I don't like the idea that older = masculine, dominant. It's an age old view that really has little merit inside of the bedroom. If I were to be with someone my senior, and they expected me to roll over, there would be trouble. Likewise, if someone younger expected me to play a more masculine/dominant role at all times, since I like a variety. If that's fine for you, go for it. I think too many bi/gay guys are hung up on things like top/bottom dynamics.
Your age has nothing to do with your preferred position in the bedroom. No one has to be more masculine or feminine. Just be you. A friend ignorantly asked me when I told her I was gay, "umm so are you the girl or the boy?" "We're both guys, that's kind of the point."