after being together for over 2 years my ex f19 got with a mutual “friend” less than a week after our breakup. For years I m18 hated this guy because of the fact he had a clear interest in my gf our entire relationship. she assured me i had nothing to worry abt and we made fun of him together for years. after seeing this i felt so sick and betrayed. it was only a few weeks after when i reached out and she ultimately left him for me. this is where i should have been content and honest abt my feelings but despite getting her back my anger at the situation was still present. confused and angry i felt the need to get back at her. i reciprocated her actions by befriending a girl who clearly had an interest in me, but ultimately i took things too far as we hung out and kissed one night. overwhelmed with guilt and shame i broke up with my gf and lied abt why. now months later she’s reaching out in an attempt to be friends. ik im the a hole here but advice is much appreciated.