Most Helpful Girl
Hmm. I think it's odd he asked you if you wanted him back. Maybe some part of him is angry about the break up and this is his way of getting you to notice his new relationship. It all feels kinda premeditated. Like his odd way of coping with the loss of you.
But I'm the end he's bad for you, as you said and it's completely normal to feel jealous. I know I have before. So don't sweat it. If he could move on so quickly then perhaps the relationship wasn't really working in the first place. You deserve better. Best of luck.