New and need encouragement

[Not Quitting]

H wants S13 to stay with him one night. While I want them to spend time together I'm really not sure how to handle this request. H is living in a spare bedroom at his friends's apartment - one double bed which he expects to share with S13. The friends have some medical concerns - one has early onset Alzheimer's and the other is showing signs that she also has it. Despite their promise to not allow H to have friends over (one in particular) I now know that OW has been there - bottle of her favourite alcohol in his room and he told S13 that the bottle was just there for decoration. WTF??

S13 doesn't know about OW. With two people with memory issues and the fact that H has a bad habit of talking in his sleep, not to mention sharing a bed, how should I handle the request?? I don't want S13 finding out about OW (something H has agreed to) - H has said OW's name in his sleep more than once (good thing he'd already confessed to the A). I don't want to deny access but I'm not at all comfortable with this.