Advice re Son please

[CrazyChicken]

My oldest is almost 21. He's still living at home but has his own 'shed' in the garden where he sleeps and hangs out (not self contained)
He's been with his girlfriend on and off for the past 2 years. She's controlling and very insecure (tells him what he can watch) cue lots of arguements and him wanting to break up. If this happens she'll turn up on the doorstep and refuse to leave and he usually ends up getting back with her. (we get dragged into it all the time and in front of our younger kids)
We've tried talking to them both and nothing changes, the latest arguement was him getting pics of an old girl friend behind her back. He's dumps her, she turns up, says she's pg but won't let him get another test to prove to us. She refuses to go so he takes her home and we said if she refuses to get out take her to the police station and let them sort it.
Anyway we've not seen him since - he's been coming in late and parking down the road so we can't hear him. Hair straighteners in his room so its obvious they are back together (oh message from her on FB saying she loves him)
I'm so up to here with it all, would it be unreasonable to kick him out? He knows she's not welcome and still he's with her.
I don't want to tell him who he can be with but they are beyond a joke and neither of them can be happy. The way my son is when they break up is just plain nasty and still he goes back.
What should I do? I'm trying not to be heavy handed about it but I think I'm losing prospective.

[madonnawhore]

My youngest brother is only a couple of years older than your son and was in a relationship like this.

I actually told him to come on here and read some of the threads about EA. The penny dropped for him like it did for me when I came here during the end of my own EA relationship.

Perhaps your son wouldn't want to come on mumsnet, but have you talked to him about EA relationships, red flags, the basic right not to be controlled or treated like shit, OP?

[madonnawhore]

I HATE to play the 'reverse the gender' card. But if it was your daughter and not your son in this situation, you'd be educating her about spotting EA red flags, wouldn't you?

[CrazyChicken]

Thanks for the new replies, unfortunately it all kicked off. Despite us saying he could no longer use his shed and he had to move back into the house he climbed over neighbour's fences to get in and bought her back too! So I've told him to leave. He can't see that he's done anything wrong, was completely bolshy about it.
Fed up with the lack of respect from him so he can now find his own place and learn to grow up :(