I'm still wondering if Dean was invited on the wedding...
I don't recall if Dean was at the wedding, though it would have likely been Teri footing the bill. Jon wanted the wedding held in his home turf back east instead of Teri's home, so Teri had to fly her friends and family out for the wedding.
All I remember is what Dean said to Jon, so it could have been at the wedding, he told Jon to be good to Teri because Dean would be with Teri more hours (on the set) than Jon and if Jon treated her badly it would be tough on everyone. Though Dean also told Howard Stern to be nice to Teri, too
Ah, I'll fondly remember the days when Dean used to get caught in the act helping Teri