Hello.
Mmm tricky one - I can understand you feeling a bit uncomfortable, I would too - but as the others said, you can't really ask him to move out for a few days. You wouldn't do it to a flatmate... I agree with you that it probably stems from him not paying rent + the minor trust issues from early on. I guess perhaps you have to think, even if you come to terms with it this time, is it a sustainable situation? You don't want to feel like this each time you go away somewhere... do you think he will ever/in the near future be in a position to contribute to the flat financially? On his side, he equally can't completely act like the flat is his home as much as yours until he is contributing to the rent (unless you don't mind him being a kept man forever

). Do you ever talk about that side of things - the future?
I think for this particular situation, you will have to try and trust him - I would reitaterate your concerns and wishes before you go though, and then if he breaches them, knowing you would be annoyed (using glasses as ashtrays etc!) then you can have words when you get back, because that is just him being disrespectful - as I think requests like that from you are quite reasonable.