Sounds like Thomas is getting itchy feet to get out
but it is far too soon to let him
can you keep him confined to the kitchen while you are out ?? just until he is really settled in ??
that way you wont have too much area to search if he has a wee.
My Hamish was terrible for trying to get out, meowing all the time, ripping up the carpet and
hanging from the door handle looking out the keyhole
never had any problems with weeing though
but with persiverance it paid off, and soon the thought of going outside did not appeal to him
have a little patience that is the key