I dont get it, i cant fathom getting pissy after sex. Either youre a self absorbed bad fuck or shes seriously psycho. There's something really wrong with people who prefer those around them to be sad.
In a sexual context, that sounds psycho.
I've seen this phenomenon in non-sexual contexts, but it's usually not "psycho" behavior. There's a reason, and that reason is often something they won't share with just anyone.
That's an unhealthy relationship if she's unhappy when you're happy, but there's often a deep-seated reason for that behavior that is often complicated. I've seen a few couples like this, and I'm speaking of non-sexual contexts of course, and the root of the problem that I've seen in the couples with this problem is a very deep bitterness that hasn't been resolved yet over a very serious wrong that has been committed against the person who is made unhappy by their partner's happiness, say, by spending all their hard-earned shared life-savings on something without mutual consent, or having a mistress. Regardless of the reason, it's usually not trivial, in the couples I've seen. One partner is still punishing the other partner and is still angry, or doesn't believe their partner deserves happiness yet because of what he/she has done wrong. Either feelings over the original wrong are eventually resolved, or they break up.
perhaps, she may have not got off...so that is more than likely the reason for her being mad when you have a Kool Aid smile after sex.
And this could be the reason.