Do you mean friends with benefits? Or an open relationship as in a couple open to sex with others?

Personally I am not interested in casual sex. I've had it, and compared to sex that you have when you're in love with someone.. well there is no comparison! Sex is much better when you're with someone you love, and I'd never have casual sex again.

An open relationship with a couple I can't comprehend so I can't comment on it. I could never be OK with that.