So I(19m) got invited by my friend(19f) to her house because she claimed her 6YO sister who I played with when being there once before keeps asking her to bring her to school so she can play with me. I agreed and spent like 2 hours there, being with pretty much the entire family(My friend, her mother, her 2 sisters) all the time, literally never less than 3 people in the room. Also while being there I called my girlfriend cus I randomly missed her but she didn't pick up. I was sure it's okay as a year ago I visited this friends house and my girlfriend (21f) was totally cool with it. Then when I got home and told her about my day she started to act very weird, I could easily say she feels uncomfortable with it but she doesn't wanna just prohibit me to do it. She claimed that in her culture a boy shouldn't visit a girls house as the sole visitor, but she doesn't know how is it here in europe . So I told her plenty of times that I didn't know she feels weird with it (it turned out a year ago she misunderstood me and thought the friends who drive with me to that Towne she lives went with me) and that I will not do it again ever even tho she doesn't prohibit me because I don't wanna make her feel like that, but she keeps telling me "I DONT CARE JUST DO WHAT YOU WANT IMMA DO IT TOO" which made me pissed as it feels like she doesn't believe that I actually do care Abt how she feels and wouldn't do it If I knew. It end up with us arguing and her saying sth like "You can even fuck her if you want idc anymore" which I think is ridiculous as she knows that this friend is deeply and tragically in love with my other friend and that she is the person to whom about I always talk abt my relationship.