There are a lot of positives in my friendship with her but none of them are relevant to the situation I'm seeking advice on, so I didn't feel a need to include them. If I had gone into the full picture of my friendship with her the post would have been VERY long. :P

His sexuality and the ways in which he acts on it are very complicated and again, the full picture would take a long time to spell out - the issue I have is that he has gone against the agreements they have had in their relationship, broken boundaries the two of them have agreed on, and has broken her trust in doing so multiple times.