Nothing in Particular

Despite a healthy sex life, you still consume a fair amount of porn these days. Idle hands are the devil's workshop, as the saying goes, and like your father before you, you were blessed (cursed?) with a strong libido that age has not much diminished.
You call upon some of your favorite scenes, the ones that you go back to time and again for a quick nut. Big tits glazed with cum from multiple men, a petite redhead getting pounded by a big black cock and calling him "daddy." An older porn star with fake tits and dick-sucking lips getting spit-roasted. You really are quite the connoisseur.
You feel the pressure start to build after a few minutes. The edge approaches, but somehow, your still having trouble getting to it. Maybe it's time to cut back on jerking it so much. Too often, you have this problem with Jenna as well, and though you tell her it's not her fault, you can tell she thinks that she's losing her sex appeal. It had happened again last night: after Zoe had enticed you and Jenna into some drinking games, Jenna had gotten very frisky: she blew you on the couch then dragged you upstairs for some serious fucking, but you hadn't been able to cum.
The shower has dragged on too long, until suddenly...