They usually suck in porn. Guy mostly pulls out, and girls squeezes it out. It's not... fun. Facials are better. Now, swallowing, there should more of that in porn.
I saw a pretty hot scene the other day, may have been Gianna Michaels, can't remember, but this guy was mouth fucking her and he blasted in her mouth, the cum was dripping out the side of her mouth, he didn't pull out at all.