Basic instinct and many other action/thriller movies from the 80/90ties, Baise moi along with many other french movies labeled as "erotic" not "porn", many japanese movies labeled as erotic not porn, for example "in the realm of senses", even the Game of throne series to name something pretty recent, and so on. Especially the french and japanese movies show often full penetration and it is still not porn.
And that Steam is just too lazy to care was discussed many, many times especially in this thread already.