"Just because there's snow on the roof doesn't mean the Boiler has gone out". Anon.
There are possibly few things more horrifying to Teenagers than the idea of their Grandparents having Sex. Yet have Sex they do - with 85% of the over 60's being sexually active declining to around 25% of the over 80's, and that decline being partially due to ever increasing numbers, at these ages, of available partners 'disappearing into the great unknown', especially for women. And, probably to the chagrin of younger players, reports from participants often say "It's better than ever".
This should not be so surprising really. There's a lifetime of experience of course ......... and ....