Sounds healthy. Why didn't she block him when he asked her out while she was still with you? Sounds like she knew you were just a temporary placeholder.

He desires her greatly, and doesn't respect her at all. That's going to crash and burn after the New Relationship Energy wears off, unless he traps her in an abusive relationship. Meanwhile, someone who was willing to leave you like that was not at all committed to you. She probably would have left regardless; he just gave her an easy fallback plan. Bitterness is perfectly appropriate, but don't pine for her. She wasn't the love of your life.

Guess she's into psychos