It’s pretty common to find porn with male-female and female-female sex and it’s pretty common to find porn with just male-male sex but I’ve never seen porn with male-female & male-male sex. Does it exist?
Yes.
There’s a pornsite called Corbin Fisher (that link is to their work-safe wiki; their website is corbinfisher dot com) that’s the net-porn equivalent of an upscale brothel. It’s actually two websites in one:
1- Amateur College Men- college age boys, most of them Abercrombie-Fitch model types, going at each other.
2- Amateur College Sex- college aged boys (many the same as from 1 since he [Fisher, whatever his real name is] claims most of the guys from 1 are straight and just gay-for-pay) and college age girls which are usually 3 ways (2 guys one girl) in which guys do each other and the girl.
If you search for the term ‘bisexual porn’ I think you should find plenty of what you’re looking for.
Or so I have read.
As a general rule (34, to be precise), the answer to the question “Does there exist porn with _____?” is yes.
Some comedian said the great thing about the porns was letting people with fetishes not only know they weren’t alone but just how many more options there were within their fetish. “Goats and mermaids? What color goat, and should the mermaid be fish from waist up or waist down?”
Of course this reminded me of a story Johnny Depp told about when he was still a big druggie. He was on a plane and he’s a nervous flier anyway, and he was stoned which didn’t help, and for reasons not even he could explain he stood up and yelled out “I FUCK ANIMALS!”
The people around him including the flight attendants and other passengers all gasp of course and people are readying for some kind of confrontation in case they need to take down the crazy guy (this was long before 9-11 and before he was as instantly recognizable to everyone as he is now; today a sky marshall would probably stand up and he’d have a laser point between his eyes). Per Depp, a passenger sitting close to him who he described as a middle aged nerdy accountant looking sort, put down his book and looked up and calmly said “Really? What kind?”
Yes it does - generally listed as “bisexual” or “MMF”. Typically one guy will be sucking another whilst he’s kissing/eating out the woman, or one guy penetrates the other guy whilst he’s doing something to the woman, or a guy fucks the woman whilst sucking off the other guy.
You get the picture I’m sure.
Just making a note that the vast majority of MMF porn isn’t bisexual: It’ll typically be a female sucking off one guy while getting fucked by the other. If the OP is looking for this type of porn I’d suggest looking for ‘bisexual porn’ and not ‘MMF porn.’
I can’t go past a “Bed, Bath and Beyond” store without snickering at the recall of a flick titled “Bi and Beyond”. Pretty much what the OP is talking about.
The 70s porn movie The Story of Joannawas famous for including a male blow job scene. The movie was based on *The Story of O *and tried for some psychological depth, along with better camerawork, in one of those attempts to make porn classier. (A topless ballet sequence! With a real dancer! After breast implants!)
The movie’s by Gerard Damiano, who also did The Devil in Miss Jones, another try at depth. (And Deep Throat, which has only one claim to depth but probably gave him the clout to try to make better porn.) IMDb has some insightful comments on it.
The 80s porn starlet Cara Lott specialized in bisexual porn.
Awesome. I really like that one.
I remember a while ago a friend of mine sent me a juvenile Email.
In it was a porn vid. As you’re watching it; it’s two guys going in on one girl. Then about half way through the video the guys push the girl aside and start in on each other.
About a 15seconds later a goofy picture of Erik Estrada covers the screen. Underneath a caption reads: “Congratulations: YOU’RE GAY!!”
So yeah, they exist.
You watched 15 seconds of guys doing each other?
… well, congratulations!
I’ve thought about this some more and realised that all the MMF porn I’ve ever seen featured has been in the gay section of the website i’ve used which is why I probably came to the conclusion that it was synonymous with bisexual (all the MMF stuff with no bisexual element just wouldn’t be there for me to see).
My ignorance has been fought. 
Sounds like Y Tu Mama Tambien.
If you ever need help with porn again, just ask me. I’m the guy to go to.
Indeed - as am I, just probably working a different section of the porn world to you.
Actually, I think I’m gonna need some sort of diagram for guy #1.
sucking + kissing/eating = bifurcated tongue?
You really want links for bifurcated tongue porn??