I keep warning Bobby that Joey is going to be bigger than him eventually and if he's still pulling this kind of stuff, Joey is going to mop the floor with him.
I've been telling Josie that about the boys for years, but the way things are going, she may be out of the house before either of them gets big enough to stomp her. They could do it together, but I think I'd have to stop it, even though they have justification ...
A "gender difference" sticking point, there ... would I stop Elen and Sally from beating up Tom? Given that our children fighting one another is suboptimal (as it were), is it worse for two boys to beat up a girl than for two girls to beat up a boy?