Try to detach from the situation. Imagine you had a daughter, niece, best friend etc would you wish the kind of partner on them? Would you be happy and excited that your loved one had this guy for a husband and had kids with him. If not, then why do you wish such partner on yourself? In addition look at the situation realistically. You wanted to date him but he was dating other people so how are you the bad guy?

It doesn’t matter he’s the bad guy or not. He’s not a match for you