well, i can't answer your question, but i've witnessed a very "romantic" elderly couple in action a year ago, and it has stuck with me until now...
a couple in their early 60s, both dressed very elegantly... standing outside of their car in a parking lot of a shopping mall... parked quite far, where there was no cars around them... an opera in full blast... and they were kissing like there was no tomorrow... even today's craziest of the youngsters don't kiss like that... so passionatly...