Having just gone through a breakup (she broke up with me), I can say that my own less admirable temptations were no different than those of many women. The fact that I controlled the impulse to hurt somebody that I felt hurt me, emotionally, reflects emotional maturity and not gender, I think.
For myself, the idea of being with someone new when both of us still have obvious and strong feelings for each other (good and bad) is ludicrous. Your best response is, "I'm glad you find her beautiful. I hope she'll help you get over me." It will drive him crazy and you'll know that by his immediate snide and defensive remark.