Ash "raping" Ripley with said porn mag (since he probably has no genitals, had to resort to rolling up a mag)
Imagine the papercuts!
I always thought the scene where she's talking to Dillon and she says the alien is waiting for them in the basement (or somesuch), and he says "there's no basement here" and she responds with a laugh... Just plain weird.
I think she was talking to '85' there. She says shes going to go look for the alien in the basement and he says "this whole place is a basement". I think any laughing she did was her attempt to find any humour at all her s**tty situation.