Am I an asshole for going to a first date after having sex with someone else?

I had a first date planned on Saturday at 5pm with a girl I had met online just last week through mutual friends. At 2pm my FWB calls me up and asks me to come over for sometime, I told her I could but I’d have to leave at 4:30. I head over there, do the deed, take a shower and leave at 4:30.

I arrive for the date and everything goes really smoothly, she is funny, pretty and overall I thought we had a great time. We end the evening with a kiss, agree to meet up again and go our seperate ways.

The next morning I receive 10+ messages from her saying how disgusting and how much of an asshole I am. Turns out through our mutual friends someone told her I had sex with my FWB a couple of hours before I went to meet her. I don’t know the whole logistics of how she found out but she did.

Now I’ll admit, I probably shouldn’t have gone to see my FWB beforehand knowing I had a date, but does that make me an asshole? We are not exclusive, nor do we have any rules about having sex with anyone else so it’s not like I cheated on her. I had never even met this girl in real life and had absolutely no obligations to her to not sleep with anyone else.

Yeah so let me know what you guys think.