Should he talk to my brother before we get into a relationship?

Anonymous
I've been talking to this guy, my brother's friend, one and off for like 10 years. We'll call him D. There's always something that comes up for why we haven't gotten together yet, but we've been talking again long distance (I'm moving back there soon) and he just told me he's ready to make it official. My brother has always known about us in the past and was always fine with us being involved. It's not that I think he'll be mad, I know he won't, but I want him to at least know so it's not out of the blue.
I told this to D and he's nervous because him and my brother have grown apart over the years and while they're still friends, he doesn't know how he's gonna react. My brother is a body builder so people are highly intimidated by him, but he would never react in a bad way. I keep trying to tell this to D. I'm sure my brother will be surprised at first but laugh it off, that's it. D says he agrees that it would be respectful but just feels nervous. It's not too much to just let him know is it? Should he tell him he's going to make it official or just tell him right after?
I'm thinking "I've been talking to (me) again and it's been all these years, we've decided to get into an actual relationship" something super easy like that but I'm open to different wording or whatever other advice. Thanks!
Should he talk to my brother before we get into a relationship?
4 Opinion