Hi Grace,
I don’t think your boyfriend’s jokes are funny and honestly I don’t think what he said were jokes but he probably doesn’t really know why he said what he said.
Close relationships bring out our weaknesses and sides we didn’t know we had and sides we we are not able to admit for ourselves.
I get a feeling that you have not told your boyfriend about all the things you tell here in the forum. I think it is always good to fully express how you feel about something in a relationship, regardless of how your boyfriend reacts.
Perhaps you want to look for yourself why you want your boyfriend to say something bad about someone else? Do you know why it will make you better? Do you feel you have to compete with the other woman?
I hope this is helpful.
Best wishes.