I'm in my late 60's but not past it yet. I still enjoy sex, though now it consists of wanking over internet porn. I'm married, but bisexual.
My ultimate fantasy at the moment is to meet a nice young smooth twink, (legal, of course), and give him all the oral sex he can handle; to bury my face in his bum and suck and lick him out in every conceivable position for as long as he wanted.
Then his cock and balls; lick and suck, lick and suck, until he shot his load into my mouth, so I could savour his cum and swallow it. As often as he wanted.