I'm 42 and happily married; the "rule" of half-your-age-plus-7 would put me at 28–70, which I don't think would be too crazy, but a little weird. I'd probably be more comfortable at 31–55. But also as a bisexual I feel like you could lineraly interpolate a spectrum of gender so the older they are the more masc they present and the more I am attracted to them.