There's nothing that has triggered me about your GF. According to your first post, YOU came here asking questions:
I am a firm believer that men shouldn't reward terrible women with exclusivity. It sends the
message to the women that it's perfectly acceptable to treat men as a convenience that can be disrespected. When men and women get into a relationship, they should be on the same level of respect. He shouldn't entertain other women, she shouldn't entertain other men. They should BOTH take the relationship seriously. If one or both aren't being serious about their commitment to exclusivity, then WTF is the point of being exclusive?
If you refused to tolerate lousy behaviour from women you reward with exclusivity, then you wouldn't be here asking these questions. If that were my GF, she would have got the boot regardless of how attractive she is.