If someone straight out asks me if they can sit on it then the answer is no. If we are talking and they are enthusiastic about the bike but not pushy, I may ask them if the would carefully like to sit on it.
As for riding it, I would have to be very sure of their ability before agreeing, and also to have known them for quite a while.
Don't feel comfortable riding other people's bikes, basically because I would worry too much about damaging their pride & joy to enjoy the ride. When I was staying with Moe in 2004 after my bike was stolen, he generously offered me a ride on Vera, but I had to turn it down as I couldn't bear the thought that something might happen while I was "in charge"!
