I watch porn with my girlfriend alot, we watch it at her place and she has quite a collection of DVDs and downloads from pay sites. We do act some of the scenes out but not often though, it all depends how horny we get while we watch it.
My fiance is the first girl i've ever felt comfortable doing this with and we enjoy it pretty regularly now I never felt comfortable discussing the hardcore stuff with previous girlfriends, I think its my hardcore addiction to dwarf porn that unsettles them