In Not a Father's Day, Ted points out a group of women in the corner who they agree is hot, but Barney states they are simply experiencing The Cheerleader Effect. Later, in the same episode, Ted and Robin point out to Barney that the members of his 'Not A Father's Day club' aren't childless by choice, because they, just like the women from earlier are attractive as a group but unattractive as individuals. Notably, in both groups, the last individual looks like Marshall.