Daughters' alliance
Last night the family was playing Tri-ominous (dominoes but with three-sided pieces). We had played two rounds which my wife and I had won. In the third round, my eldest daughter was on a good run and was clearly going to win the round. Seeing this my younger daughter decided to lose by as many points as she could because those points would boost her sister's score. Why? Simply to help her sister beat me because "daddy always wins".
I cannot recall my daughters ganging up in order to ensure one of them beat me.