I had a similar situation with the father of my kids...we are no longer together...I finally kicked him out (alcohol, gambling, cheating, verbal abuse) but would get sucked back in and allowed him to stay on the couch or son's room just for a night or two because I thought I "felt bad" for my kids. I wanted him to be able to see them. There was no way I would let him have them if he was staying at a hotel.
He did something similar...tried to be the "nice guy" and when I told him he needed to find another place to stay he got upset. They do that when they don't get their way...I finally had to write a 30 day notice for him to leave (we were not married). If didn't leave by the end of that 30 days I was going to the police for help. It sounds like he has a bad temper...you don't know what he might do. I would also suggest getting that protective order. Save your money for you and your kids...not for his deposit..please let us know how you are doing.