Just got home after having been out for the day. Left the house at 11:30 and came back briefly at 3pm before leaving again and returning just now. When I went in the kitchen I could smell men's aftershave/deodorant. Definitely not DH's. I asked DH if he could smell it and he said that he'd thought the same when he first came in. I'm now terrified that someone has been in the house whilst we've been out.
We've checked all the doors, which were all locked, and there's no obvious sign of anyone having been in any of the rooms. House was brand new when we bought it over two years ago and nothing like this has happened before. The only other people who have a key are the people we've been with this afternoon so it can't be them.
Someone please tell me there is a rational explanation for the smell before I spend all night sat awake with a kitchen knife.