I mean Pacey said it in their 615 fight. "What keeps our friendship going year after year after year" "We don't, under any circumstance, talk about sex. I may be having it, you maybe be thinking about having it, but we don't, under any circumstance, discuss it - that way we avoid the awkwardness"

I mean if we have to take barely an PJ after season 4 and them barely acting like they had this epic relationship, then I'll take that. They weren't immersed in each other's lives because they wouldn't have been able to handle them with other people. They were friends but not close, because any closer and they would have had to face their past relationship and the possibility of getting back together.