I'm thinking "talking" to him may just open a can of worms that has the potential to explode in a bad way, given his temper.
This guy poured beer on you, in front of other people! with no remorse. While that may not seem like the most horrible thing, it's a massive sign of disrespect. I remember my ex once spit in my face, at a huge event here in my city. I remember being so shocked. I almost wished he had slapped me. It was so demeaning.
I feel awful that you are dealing with this and hope you decide to stay at your parents and not go through with this house purchase.