I'm currently deployed and obviously my girlfriend and I are very excited to get back in the bedroom. When we have sex it's usually very intimate, which I'm very happy with, but recently she made comments about wanting to be rough. I asked her about it and she said sometimes she doesnt want to make love she just wants me to fuck her and didnt want to bring it up earlier because she thought I'd think less of her. I dont and I want to make sure that shes completely satisfied and being rough does sound fun. I asked her where what she wants to do and she said she doesn't know, I asked her where the line is and she said there is no line. I dont want to come in with a gag and whip but I also dont want to be afraid of hurting her and leaving her unsatisfied. Where can I start with rough sex, what things can I do or say?

Td;lr girlfriend wants rough sex and I dont know where to start.

Edit: I should add that she has been raped multiple times and i dont want to bring back those memories.