My husband is close with his brothers wife, this has been the case for many years, long before I came on the scene. I’ve always known this and been ok with it, they would have nights of them 2 going out for drinks etc as they are good friends. However recently they’ve been messaging daily, I haven’t been looking at his phone, but when we are sitting together her name flashes up several times...nothing inappropriate as far as I’m aware. AIBU to think this is a bit weird?