LW1 - never ever parent somebody elses kids, they don't listen because they know you dont' mean squat to them, so, what's the point?  And parents can get very agressive when someone as much as blinks in the direction of their perfect children.  Better choice is to move to a different part of the playground and enjoy till the other area is clear of the monster child.

LW2 - parents need to mind their own business here.  However, the couple should know that all is not equal as they believe.  Assume they get married and have a family, will both mom and dad give birth?  Will both mom and dad have hanging boobs filled with milk that needs to be pumped?  Will both mom and dad get up and take care of baby each night while one of those parents has to go to work in a few hours?  It's not all equal.  Things need to be split up such that not one person is doing all the heavy lifting.  That's where the "equal" thing gets complicated.  But hey, enjoy the pre period.  It's a blast while it lasts.