It's now called "Punch Buggy". "Blue punch buggy (punch in the arm) can't punch back!
How they put up with the three of you in first place not counting the "bug" game is a miracle ;D! Your poor mother was dealing with toddlers and diapers for over 5 years.
What cracks me up is that everyone seemed to play this game but everyone called out their own unique names. We never did the punch thing but did do "Tied, you owe me a Coke!" if we called it out at the same time and whoever won the Coke quick-draw got that Bug scored to them. But think about how we kept ourselves occupied for hours without the need for DVDs or all the other nonsense they have these days.
BTW, the worst thing for my Mom was never having a little girl. You know how some girls are never good enough for Mommy's son? Not in our house! Man, any girl who walked in the door was such a relief from all the testosterone that my mother welcomed them with open arms.