We all know Stephen Colbert as a whip-smart comedian with a penchant for biting commentary. But it turns out the sarcastic funnyman has a soft side, too. Before taping his “Late Show” on Monday night, he took an audience question about how he met his wife, launching into a very sweet story about the couple’s meet-cute. A younger Colbert was back home in Charleston, S.C., having just decided to end a different, serious relationship, when he and his mother went to a show together. “So I go, I walk into the lobby with my mom,” Colbert said.