I found how to get the 4th ending. so when you are about to take a shower, you get 2 choice, "be careful" or "being paranoid". You choose the first one "be careful". then when he ask you to trust him about him bringing you home you choose "don't trust him". when you get to where the bunny is trap you choose "he's being a sadist" than "please" and when it gives you the choice to decline or take his hand, there's now a third option, "call him out". and here you go, you get your 4 ending. hope this help.