Okay, firstoff, i've never even heard of breakup sex. And i'm pretty savy on the subject.
Second, there's an estimate 10% topic on sex in this forum.
You know, the more people talk about it, then less inclined i believe they have any.
Frankly, normal people don't want to talk about thier sex lives.
But no, I cannot say I've ever had breakup sex, so I cannot compare it to makeup sex. Ussualy in a breakup there's a breif moment of silence while the brain registers it, and then sets itself to attack mode and planning to destroy your ex.