The next day, Barney goes to the apartment and laments that once gay men start getting married, everyone else will get married, too (because whatever gay people do, everyone else starts doing six months later), and single life as we know it will be ruined. Marshall points out that just because James is getting married doesn't mean things have to change, and Barney points out that the four of them have changed. Ted says that his sister married someone he didn't like, but he realized he had to support it anyway, and tells Barney he should do the same with James.
The next day, Barney visits the apartment and worries that when gay men start getting married, others will follow suit, causing an end to single life as they know it. Marshall disagrees, saying that James' marriage doesn't mean things have to change for everyone else. Barney agrees with Marshall, suggesting he should accept James' decision like Ted did with his sister's marriage.