Hey @happy b do you have a balcony you can put them on in boxes? lock the balcony door, if they want to inspect it just say your mrs has the key, she's not in. Also cook a massive curry with LOADS of garlic and when they are there act real nonchalant like having them over aint no big thing.
My mate had a surprise visit from the gas company, something he did in his loft disturbed a vent from a downstairs flat. He was out when they went around, his 18 year old son stupidly let them in. The guy saw what was happening in the loft and told the son he wouldn't do anything about it but they needed to get it all out by the next day because he was coming back with a colleague to do some work!