It is a bug, I lost the game at the win screen if you read what i said then you would of understood that
What was the "mission objective" of the setup? Reaching 100 hornieness, no matter what. Or was it having fun under the eyes of Cheemy without her bonking you.
To tell it in fluff, your goal is to make the other toon so horny that she will follow you to your room for more. But alas, Cheemy is suspicious and will not allow it, if she thinks you two will do nasty things. So even if you reach max horniness, if Cheemy bonks you, you cannot reap the fruits of your achievment, because "you ded".
While overanalyzing silly fun games is fun, it only were a bug, if it were established that the only thing needed to win, is 100 horny. But with the "ded" thing, I believe it is quite established, that this losing condition will trump the winning condition.