The fact that I've been happily married for 29 years means the topic rarely comes up for one thing.

I think that female solo cyclists have their radar on pretty good for other solo cyclists who bring up the subject of casual sex. It's probably a concept they have to guard against rather than encourage. I would not want to make a female I met on the road feel awkward or uncomfortable or wary of putting in some miles together. Also a poor warmshowers greeting.

"oh.. a lone female traveler, wonder if I should start talking about casual sex?"

If it happens it happens (for others) but I can't see bringing it into a conversation with strangers.