The Daily Mail reports on the occasion, noting that nobody knows why exactly they were all hangin' out, they did seem to be celebrating something.
Although it seems awkward AF, we all know that Demi and Joe are super close friends, and Demi also cleared up that she and Wilmer are on friendly terms, so, all's chill in the land of Demi's ex-loverz.
¯\_(ツ)_/¯