DH's sister, who is 18 this december, is coming to stay for the weekend with her boyfriend. They have been together for two years and she is very sensible.
I know that they are not allowed to share a bed at her mothers house, but I see no problem allowing it here. It's not an issue I want to bring up too, so I am thinking if MIL says nothing, we will just go ahead and let them. Is this wrong?