FOCUS ON COCK
Try and talk dirty about cocks while you jerk off. Say how hard you are, what an amazing cock that is in the movie you're watching, loudly admire the veins, the mushroom head, the hanging balls. Be cheeky and prepare the movies you want to watch ahead of time to make sure they include the juiciest specimens with plenty to talk about.
You get bonus points for engaging your bud: ask them what they think about the movie you're watching, tell them how thick their dick looks and how horny you are from looking at it.