I've tested this with two different endings, the Adra and Foursome endings. After both sex scenes I get the normal waking up on Tessa's ship, and then the next choice (Get Mad, Unfazed, That's Hot), and regardless of what choice I make there, when I hit next to end the scene and get off Tessa's ship, the next button just does nothing. I've clicked it, I've used the 1 key, I've tried multiple times from the start of the quest. Once I reach that point I'm completely stuck and my only option is to load a save.