Hey well done you for doing both of those girls a favour!! I am sure that they didn't know he was cheating on them also.
Not vengeful just helpful and your well shut of him - he sounds like he is going to be a serial cheater for the rest of his life.
God I read back through some of my posts on here and I sound like a right man hater - I'm not but I really can't stand bad behaviour and if its not something you would ever dream of doing to somebody you cared about - its not right to accept it from other people who supposedly care about you.
Go girl!!! On to your new life