I remember seeing a very strange, most likely direct-to-video, horror/sci-fi movie when I was younger. A group of friends pick up a crate and are instructed to hold it until an unknown party retrieves it from them. The main characters are upset about how the deal is going down but take the box back to their place regardless. They eventually open the crate even though they were told not to and discover an alien creature with a rather phallic tail. I believe one character rationalizes that the alien is a type of monkey.
The movie continues with the alien either killing the characters, or convincing them to kill each other or something.
Eventually, in the end, only a single person remains. She and the alien creature have some sort of strange alien love scene. I don’t recall it too well; most likely I blocked it out of my memory.
Any help to finding the name of this movie would be appreciated. I feel like the name is something like, “The Box”, “The Package”, “The Crate”, etc. but I could be wrong.