It's "real" in that yes you can just rub your junk on stuff, including someone else's junk - it's not real in that it's not, like, something people actually do, or that feels particularly stimulating for both partners just because of the geometry (it's borderline impossible to get your bits to mutually line up). Basically as it's commonly depicted, it's not real. There's stuff you can do with mutual thighs that can be quite nice if it works anatomically for you and your partner, but I've never seen that done in porn (and believe me I've looked)