<human>: Can you condense the text into three sentences or less?

My best friend recently got dumped and his behavior is starting to get concerning. He seems to think the breakup is a test from his ex. She has been rather confusing and is bad about expressing her thoughts. However myself and another mutual friend have hung out with her since the breakup and it is apparent she is done. I have told my best friend he needs to move on but he basically is ignoring everyone's advice. He has even been lashing out at friends. 

He works with his ex which is a bad thing. The breakup is going on 2 weeks tomorrow. They were together a year and a half. Yes that is a decent amount of time and I understand he is upset. But he is almost starting to become obsessed with winning her back. He wrote her a long letter and then told me he was also working on a book for her. I am hanging out with her today and he knows this. She posted on Facebook a couple days ago a cake recipe saying it looked good. He proceeded to make this cake for her and wants me to give it to her today when we hang out. The ex is completely done and is honestly getting freaked out by his behavior. Also she hates cutesy things such as that. His actions have pushed her completely away as previously she said she wanted to remain friends with him but now does not even want that. I want to help him move on but he seems to not care about what you say unless you are telling him to keep trying. Does anyone have advice? I don't want to tell him he is acting stalkerish but he kind of is. He has done a lot of other inappropriate things and the way he is talking about the situation is raising flags for me.
<bot>: best friend is acting really irrational and won't accept being dumped. Keeps trying to win ex back by doing creepy things