To be honest - I don't think his ex girlfriend is an ex. He fooled around on her with you and he's continuing a relationship with her. He wants to keep distance between you and his mother because she likes Sally and they consider you the 'other woman'. Sally had him 1st. Your boyfriend, Sally and his mother know all about this -enabling him. Clearly he has 2 women - no doubt. Sorry to be the bearer of bad news.