Would what she did get you mad?

I was at my FWB house and we were supposed to go get frozen yogurt. When i got there she said she didn't feel like walking so i said thats okay. which i was okay with. Then she got on her laptop and got on stickam on the singles page and started talking to other guys and told me to get off camera or else they won't talk to her. I was okay with it until she started giving them her skype and msn. I sat there for 15 without saying a word and she didn't really care she just kept flirting with them. Eventually her brother that was watching what she typed said OMG you actually like this guy? after that I lost it and just walked out and said "*** this Sh!T i'm leaving." She just said are you serious?? when i left. She texted me later saying sorry but i just ignored it. Yeah i do think i have some small feelings for her but we often get jelous of each other. Yes we have had before just incase that matters.