FG's smile shows very well the liberation he felt when Norton let out all the bad feelings he had inside. However, Hullabaloo looks sad, overwhelmed by everything Mike's been holding inside for years.

Their differences in personality 😭. I want to comfort Hullabaloo so bad. He is just a broken man who has the innocent wish of having a happy family

I think Mike doesn't know how to deal with all those bad emotions, this is why he tries to smile even though he's crying and completely broken..