Per one night he decided to leave me, then started to write to my best friend whom he does not even know? WHy?

[Deimy]

He even said " I am enjoying talking with her" when she said they did not even talk a lot

[Anonymous]

Because chances are she’s hot, or somewhat pretty. Maybe he’s trying to plow her. Sounds as though he’s trying to make you jealous or get back at you for something you may have done.

[User3191989]

You need to leave this guy hun