I'm moving to a new house (rented from family member) and he's put a new door in which features this type of lock; you lift the handle and turn the lock by hand to lock it from the inside, but you need a key to lock it/open it from the outside.
If I was to lock it from the inside, would somebody with a key be able to open it from the outside, even if it it locked on the inside?
Reason I ask is because this family member has poor boundaries and I made it quite clear to him that I dont want him just letting himself into my home when he feels like it. I said I would just put the key all the way through the lock so he wouldnt be able to open it from the outside, but he has gone and put this type of lock on the door and i'm wondering if he is doing this so he can let himself into my home?