My tenant has a boyfriend who seemed to be in the property a lot as her guest. I questioned this casually when doing repairs and was told the boyfriend had his own property and when he stayed over he was her guest. I agreed this was not my business as the tenant is entitled to peaceful enjoyment of the property and to guests. A few months into Covid, the boyfriend admitted he was living there full time with various lengthy sob stories. I turned a blind eye as Covid progressed, as I didn't want to cause anyone misery during Covid and I understand the law does not permit me to move him on during it anyway. It is well over six months. What rights, if any does this boyfriend have? He has not asked to be on the tenancy and I do not want him on it as he is a high maintenance and difficult character. Can I ask him to leave before or after the end of Covid? If he refuses, what authority can I use to get him out.