I don’t normally have anyone under 18 in the house, so was not intending to bother with any particular security.

Air rifles
That’s an interesting conundrum and I suspect we will have to wait until the situation arises to find out what the police and courts do.

It would be ironic if a teenage burglar nicked your gun and you were fined £1,000 for allowing him to do so!

In my view you’re in the clear provided the house was properly locked at the time.