A reader asks: I’m aroused by the idea of being cheated on; am I normal?

You dream about the average guy’s worst 
nightmare? Probably not normal.

Society primes men to believe that women view sex and love as inseparable. (Whether women truly think that way is another story.) So when a man imagines his partner wrapping her legs around – and thus falling in love with – another guy, he usually experiences feelings of shame and rage that overpower any inkling of arousal, says Dr Katherine Hertlein, an associate professor of marriage and family therapy at the University of Nevada at Las Vegas. For you, shame elicits a different reaction. “Some people have been conditioned to associate humiliation with arousal,” says Hertlein. “For example, if you’re masturbating and someone walks in, you’re humiliated and at the same time aroused. Your body starts to associate the two.”

If you keep your fantasy in your head, you’ll be fine. But if you want your gal to stray or do something that could harm your relationship, you should see a sex and relationship therapist. 
You can find therapists that specialise in sex and relationships at Therapist Directory.