Well then why do 80 something still have sex when they are too old to reproduce? Or how about the fact that people who got rendered sterile but still engage in opposite gender sexual relations (cancer treatment)? It has more to do with the nature of the lifestyle than whether or not the behavior actually reproduces (incompatible equipment, early heartbreaker acts with someone older, number of sex partners, accompanied substance abuse, etc.)
It’s a human reproductive process. Duh. You really don’t understand the natural function? People get old and still do it. My spouse and I are unable to conceive anymore, but we still have our animal instincts.
You seriously don’t understand my point?