The 30-year-old actor said that his own confusion about the concept of matrimony failed to get in the way at the weddings of Christina Hendricks and Elisabeth Moss.
Moss, 27, married Saturday Night Live's Fred Armisen, 42, in Long Island City last week. "They got right down to the ceremony," Kartheiser told Us Weekly.
"Not a lot of hoopla and waiting around. Really simple and beautiful. Elisabeth said stuff that made me cry. They were really just speaking to each other and the people they loved."
Kartheiser stated that the "smaller" Manhattan wedding of Hendricks to Geoffrey Arend in October also left him in tears. "I've been around for a lot of their relationship. Geoffrey was a really good friend of mine, and when he met Christina I saw his whole life change for the better.
"It's an inspiring thing when two people can adapt, give to each other and help each other grow," he added.