I think it is all over the place. I'm 77 ... while that might be a bit on the older end ... I find lots of guys from the mid-60s on up. Lots of guys in their 40s & 50s too. I think this site covers a big age range.
75 ... met a local guy on an on-line site. He was the very first non-medical male to ever touch my dick. His was the first I ever touched. His was the first ever in my mouth. His mouth was the first guy's mouth it went into. Guess I was late getting started.