UK Landlord Forum / Life

Good evening,
I have a question about a property I let in Scotland. When I let it originally it was to a couple who split up and he moved out. The female stayed put with her daughter and I did a new tenancy agreement in her name only. They then got back together and he moved back in however the agreement stayed in her name only. They have now split again ( both still in the house) she has found a bigger house to let (2 kids now) bloody right next door. He wants to stay put but I'm not keen. The council have said he has the right to stay as he still thinks it's a joint tenancy, I never got him to sign anything when he left and I have been reading up and I really should have. In light of this what are my best option for damage limitation if he decides he's going nowhere fast. I have as a job supported individuals with tenancy issues and I know the local authority can be quite brutal I've even witnesses them say to tenents to stay put even after NTQ has been served and to let the landlord take to court. I'm guessing this is because if the person is homeless it changes their legal responsibility to rehouse.
Sorry about the long post any experience to share would be appreciated as would advice to get out of this potential hole. 😱😱😱