I think I've made sense of it now that I've rewatched it!
Comments
I think they were the same people. He's more aggressive with his wife because he wants out of the relationship and more loving to his girlfriend because he wants to be with her. He has two places after all. Not sure about the spiders? maybe it symbolises him being stuck in his marriage because of his unborn child. The spider recoiling in terror was maybe supposed to symbolically represent his wife and how she's afraid of him. I think the car crash actually happened and she found out about it.
well I was sorta right.