My friend's boyfriend hates me?

I don't need my friend's boyfriend to like me or be friends with him, but he seems to be really rude to me and only me. He treats her other friends fine, but he always makes snarky and rude comments about me in the company of other people. We've never argued or anything and we're not close so I don't get why he's so rude.

He always tries to bring me down in a group situation by saying I'm dumb, average-looking etc. Even in front of my friend, who doesn't say anything she just keeps quiet and goes along with him. Someone called me pretty the other day and he said really loudly "She's ditzy and not really pretty. My girlfriend and I are better." LOL. Me and him used to "talk" but that was ages ago, and it wasn't that deep.

Still why is he being so rude to me? How should I respond?

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1 y
He literally used to say I'm "ridiculously hot" when we were involved, so not sure why he is now calling me all these horrible names lol. I don't want his approval anyway since he's not a nice person, but I don't know how to respond.
Updates
1 y
It's embarrassing because he says these things in front of others and it's always in a sarcastic way.
My friend's boyfriend hates me?
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