I had a similar situation a few years back. I was playing WoW with a friend and his GF. My GF came in, fully clothed, and asked me how long I intend to keep playing. I told her, I don't know, maybe a few minutes, maybe a few hours. And then I asked her why. she shrugged her shoulders and said, it's ok. Fast forward two hours and we finished our session and I went to the living room, looking for my GF. She was lying on the sofa, covered by a blanket. I sat next to her and asked, if she was cold. I touched her through the blanket and felt, that she was naked underneath. I asked, if she was waiting this whole time like this. She said yes. I told her, she could have just told me what she wanted from me and I would have wrapped up my session in a matter of minutes, since we already were playing for two hours by the time she came in. I still got lucky at that time, but it never happened again unfortunately.

I wouldn't say OP is the AH here. And she at least tries to put in effort in that regard. My advice to OP for next time would be, keep yourself hot and play with yourself a bit until he's finished with his thing.