I'm sorry Brooklyn. I'm also pleased for you that it's out in the open. This may not be very comforting for you, but he must have felt sufficiently safe to tell you about it finally. That's got to be a baby step hey?
Now is the tricky part. You will feel angry. Justifiably, because you know it's trickle truth, and you know he's manipulating you ...
The trick for you will be to use this experience as a true test of your growth. Let the feelings of anger and disappointment wash over you. You'll want to lash out. You'll want to hurt him as much as he is hurting you. You are stronger than that now. You can take this in your stride and demonstrate you are a different person.
You can do this.
((BM)) V
V
Never make someone a priority, who makes you an option.