is it bad to dislike/hate ur partners’ ex?

guys hear me out. is it ok to have a strong dislike for ur partners ex? i legit cannot stand her, for the things she did, the way she taunted my partner after their breakup, and the fact that she’s with a man after cheating on my gf with one. i’ve been with someone who has lied about their ex being crazy, or terrible trust ik the signs. i’ve seen proof, messages, i’ve talked to ppl who were around during that time, my partner is not lying for her benefit. i just don’t know if it’s unhealthy of me to hate her? it’s a festering hatred? pls tell me someone relates, i literally can’t stand her!