With all the crazy things that happen in porn movies, you'd think everything would be covered.
But so much of it is rote and you never see common sexual practices, like couples masturbating together.
Now this is common in F/F and even M/M porn, but why not M/F porn?
Is it that straight men are afraid of seeing a guy jerk himself off because it's too close to watching gay porn? Well, probably 50% of porn movies involved the guy jerking himself off onto a woman's face or body (and this could still involve that). Is it fear the man not satisfying the woman and showing the inadequacy of men? Women frequently masturbate while having sex or giving blowjobs during movies. Maybe it's that when you're paying the actors you might as well pay them to fuck?
This seems like a potential niche or at least something that could appear in a feature, for example. But so far I haven't seen one scene and I'd like to.
*Anecdotally speaking this is not an uncommon sexual practice. In fact, it's hard to imagine many sexual practices a M/F couple can do besides masturbating together or mutual masturbation while watching porn. I mean it's kind of hard for one partner to watch a movie if they are giving a blowjob and if you are having sex, i suppose it's possible, but it just doesn't work too well, you know. So just saying… 
Edited by - nylonsoles on Nov 20 2016