This conjuring ability to create fantasy scenes in our heads that literally bring us to orgasm when conveniently paired with our dextrous appendages is an evolutionary magic trick that I suspect is uniquely human. It requires a cognitive capacity called mental representation (an internal “re-presentation” of a previously experienced image or some other sensory input) that many evolutionary theorists believe is a relatively recent hominid innovation.

When it comes to sex, we put this capacity to very good—or at least, very frequent—use. In a now-classic, pre-Internet-porn (I’ll get to that later on) study by British evolutionary biologists Robin Baker and Mark Bellis, male university students were found to masturbate to ejaculation about every 72 hours, and “on the majority of occasions, their last masturbation is within 48 hours of their next in-pair copulation.” If they’re not having intercourse every day, that is to say, men tend to pleasure themselves to completion no more than two days prior to having actual sex.

She said: “I do eat healthily and am careful with my diet but not all the time. There are times when you want that piece of fried chicken. That’s my big weakness and there’s nothing wrong with that.”