So it turns out that jerking off isn't just for perverts, priests and serial killers anymore. Well-adjusted people in loving relationships like to do it too! Sometimes they even do it together!
Okay, so maybe we already knew all that (or at least had a sneaking suspicion about it). But even if we've evolved past the hairy-palms-and-blindness masturbation guilt of childhood it's nice to be reminded that masturbation isn't only the work of the self-indulgent teenager at heart. These guys are so selflessly invested in each other's pleasure! They're holding hands for Christ's sake!
Thanks to Vinny for the tip.