Honestly I'd rather leave it somewhat vague, so that possibly interested parties can contact me and I can judge on a case by case basis whether I am interested. I don't have a hard age cutoff .. some couples in their 40's and 50's have more youthfulness and sexiness than many couples in their 20's and 30's ... but I feel like I'll know it when I see it.

And yes, for the most part, I do mean that both people are bi ... though I guess you are right, that is not necessarily a requirement that the woman be bi as well. I find I like couples where the woman is bi too, though, because she tends to understand that excitement that I feel a bit better, and it also opens up more possibilities with me and a female partner down the line.