Going to her bf’s family wedding as a couple for a weekend without me (cuck)

So, B has invited Lola to a family wedding he is attending very soon. They would travel together, arrive together, eat together, she as his plus one in a double room. He has already told his family of what he has going with my wife and they are chill with it.
She excitedly told of the invitation and said she would love to go with him.
I just don’t know how to react.
Advice welcome please.