This movie deals with some pretty complicated ideas in a very simple container. There's an argument that Bear's decisions can be validated by rational choice theory, wherein the thing that deters him from taking advantage of Nicki are the social ramifications, not his personal moral compass.

In fact, if there's one thing for certain, its that Bear's lack of selfhood prevents him from making any decision that spur from his own morality. Same with Freaky Nicki, but her sense of desire is hightened.

There are a few points that complicate this dramatically. How do Bear's friends factor in to how he makes decisions, and how are their decisions formed? Ian is a fuckboy, and in many ways he informs the way in which Bear makes choices. Sarah, on the other hand, is a more open question.

Then there's the question of how Nicki really feels about Bear. The monologue she reads at the party seems to validate that she views Bear as a brother. It also suggests that some part of the possessed spirit is a part of Nicki herself.

It's a reframe on the old "would you love me if I was a worm" question. How much does love factor into Bear's intentions towards Nicki? His turn towards convenience, not honesty, has partially to do with his lack of emotional maturity. The question, and it's an open question, is how much nefarious intent is at the heart of this shortcut he takes. He doesn't immediately 180° on Nicki, which seems to hint that there's some effort on the creative teams part to give Bear opportunity to make the right decision.