It was an "auntie" that left that lipstick mark on his collar, President Obama explained Tuesday evening at the start of a White House event marking Asian American and Pacific Islander Heritage Month.
"I do not want to be in trouble with Michelle," he joked. And to the anonymous off-camera auntie of one attendee, he added: "That's why I'm calling you out." The White House has a 6+ minutes long video of his remarks. His explanation comes in the first minute. CBS News has a shorter version focusing on the lipstick comments here.
According to the president, the lipstick was a very visible sign of the warmth he was greeted with at the reception.