Basically, I'm going to buy a second car (with cash) to play around with and am going to loan my daily driver to my live-in girlfriend while she saves up to buy herself a vehicle. She moved in after having to get rid of her vehicle because of it being a pos and not being able to make it from her place to mine (\~100 miles away). She complains about being bored and being stuck at home all the time. I pay all the bills and I pay the loan on my car, including the insurance to which she is on, the agreement for moving in was she pay for groceries and the fuel in the car.

When I came home to prepare for checking out the car she got irrationally annoyed and snapped at me asking why I don't just buy her a car instead of loaning her my Civic and she'll pay me back? I'm not entirely sure where this came from and now I feel extremely guilty. I didn't even think anything of it until now. I thought I was being nice and now I feel like shit. I hate people owing me money, I do not loan money to anyone because I hate having to deal with people not paying me back, especially not my GF. Am I being selfish?