My SIL once asked if I'd like to give her a foot massage. Trying to be the gentleman, and like a complete imbecile, I politely declined. She has just begun courting a good man, and I didn't want something as innocuous as a foot rub to cause a rift in their relationship. She ultimately married him. I confess I've regretted my decision (to decline) every day since.
If she hadn't been dating at the time, I would have gladly accepted her request.