We're currently having some work done in the back garden and whilst I don't have any particular reason to distrust them I do feel a little uncomfortable around the workmen. The other day I was just popping round to the shop and went out to inform them I'd be out so the house would be locked up (they use our toilet so thought it only fair to inform them).
In response they told me not to worry about locking up, they would keep an eye on the house for me. Now this wasn't what I had in mind but I couldn't see, short of telling them I didn't trust them, how to tell them I felt more comfortable if I had locked up. I felt pretty on edge whilst I was out and didn't do everything I meant to to get back in time. When I got back I heard some pretty quick movement and just spotted one of them going out the back door when I got to the back of the house. I haven't seen anything missing and have no proof he was anywhere but the toilet but my suspicions are even higher now.
How do I lock up whilst they are at the house without offending anyone?
They'll only be here one more day so I'll probably just stay in but I wanted to know for the future and perhaps others faced with the same problem.
Edit: I can confirm that it isn't unusual in the UK to offer hospitality to people working on your property. Tea and access to the toilet are very common.