I dread hearing this but it is understandable
You tell her that she looks beautiful, and you remind her how much your parents liked her the first time she met them -- so you're sure that her boyfriend's parents will feel the same way. What you don't tell her is how nervous and jealous you are feeling -- because you know that if the weekend goes as well as you anticipate it will, that it will be the prelude to her boyfriend asking her to marry him -- and if and when he does, you know that she will say yes.
She’s completely his when he wants her. He never leaves her unsatisfied
This is inspired by actual events. My wife has shown me outfits she planned to wear on dates while I was going to be gone.