Ya he def hiding something, my douche bag ex did that same smurf. He would change the names of girls to guy names so then I would think anything about it, serioulsy busted the door down to get his phone back. Leave him! You'll look back and be so happy that you did. Good luck!
That is beyond sketchy hunnie.. The fact that he went out CLUBBING while you had just given birth would not fly with me. That's bullsmurf. I would leave then. That's super immature. But i'm sorry, if you have nothing to hide then he wouldn't have reacted that way. I'd leave. Pack your smurf while you're in the room and go. I'm sooo sorry.