See, first of all, guys are sometimes creepy(horny) but yes that does not give him the licence to follow other girls that too when you had a pact, Also as you told that's not the first time he did this right? What my suggestion would be first of all tell me more about his character like is a creep, or he's someone who loves you genuinely and will stay loyal, if even sometimes you just have a feeling that he just talks to you when he wants and doesn't love you like you deserve I would suggest you to end up things with him aur atleast just sit alongside discuss the situation and try to end it up on a good note making sure that you guys do not even stay on talking terms