New Delhi, Sep 11 (ANI): It might be hard to believe but not all men want sex. Actually, some hardly want it at all, and apparently that's normal. It's widely believed that men are always up for it, but a sex researcher reckons that men just can't say "no". Andrew Smiler, author of Challenging Casanova: Beyond the stereotype of promiscuous young male sexuality, says that men don't realise they can actually refuse sex. He said that guys find it hard to say "no" because they're concerned about how the girl will respond, including concerns that she'll think he's either some type of wimp or gay.