A bit earlier I realised T wasn't in the house. I guessed he had gone out taking photos, but was a bit embarrassed that I didn't know how long he had been out in the dark for. Or for certain what he was wearing, or what he had with him.
He has just come in with cold feet, a big smile and lots of photos. He agreed with my idea that I put a note up on the door with blutack so he can move it somewhere obvious as he goes out. Telling me would be better, but hey!