“If you’re a married man, you might love your wife, but you won’t get as strong an erection for her or have as strong an ejaculation if your testicles know that this woman is yours alone. Nature is conservative, so your testicles won’t work any harder than they know they have to.
But if your wife has been away at a conference and there’s a chance that she’s had sex with another man, you’ll get a stronger erection when she comes home.
If she has had sex with another man, that makes you really hard.”
- sex therapist Susan Block, in Anneli Rufus, “The Intellectual Sex Fetish”, The Daily Beast, 07.29.10