santin
Explanation
This comic is a Christmas-themed joke that plays on the "Santa isn't real" trope. In the first panel, Santa announces to children that he's got to deliver presents to all the boys and girls, with an ominous "bye bye Santaen" (a play on goodbye). Later that night, a woman asks a shirtless man "Want to... you know?" and he replies "Getting into bed for the night?" -- implying Santa has come home and is just a regular dad/husband. The final panel shows someone telling him to "put it back on," referring to the Santa suit.
The caption reads: "Statistically, this happened for at least ONE of you" -- joking that given how many children sit on a mall Santa's lap, at least one of those Santas is statistically likely to be their actual father who goes home, takes off the suit, and gets into bed with their mother. The humor comes from the uncomfortable statistical likelihood of this mundane but slightly awkward scenario.