To you, what's the appeal. EDIT: I'll take a stab. (1) validation - that someone with that high an SMV wants to pass on YOUR genes affirms that your biological imperative will be fulfilled and as an emotional corollary and incentive, proves to you that you're a pretty special guy. (2) sensory experience - the variety of touches, postures, sights, and so on is interesting (3) intimacy - we get off on communication (4) masculinity - you feel like you're doing your job