My exW did the same garbage with her MLC PA - I think the show is so that people will "know" they are together. It's kind of like hickies to teenagers - most of us grow out of that also.
I agree with Celestial on keeping the independence. And don't worry about being "friends" especially while he is with OW. Build and live your life as if this is how it will be - you and D.
Don't be jealous - at least what you had b/4 MLC was real.
This has been a turning point to a better M. In 25 years will either of us will remember much about this time? Because in 50 years neither of us will remember much of anything.