"What?"

It made a kind of sense to her. Her relationships always got worse in proportion to how 'serious' they were. She probably could have carried on with Rayne indefinitely if she hadn't attempted to turn their 'arrangement' into a relationship and in so doing forced Shego to notice how crazy she was. Sex in the prior knowledge that romantic engagement wouldn't work out - what could possibly go wrong?

"You just said nothing else had to change."