My mate's gf is a size queen and unfortunately he doesn't have the inches. It's a big problem (pun intended) and, according to them both, their fix is to let other (more impressive) guys fuck her while he watches. Thing is, I know he hates this. He's a man and he doesn't want to believe he can't do the job as well as another guy. It's cutting him up but he doesn't admit it, says it's cool, etc. Now the issue is I've been invited (by her) to be one of the guys who fucks her in front of him. It should be an easy question because she's v fit and I'd love to dick her but is it too cruel on my mate? On the one hand it'd be a massive turn on for me to do that with this girl but I dunno if it's ethical. Would you or not?