parallel play

par′ al•lel – adj. being or moving in concert, n. a resemblance

co•op′ er•a•tive – adj. working with others

play – v. act out; perform; participate in a game – n. a dramatic performance

par′ al•lel play – n. children play next to one another, doing much the same thing, but they interact very little

co•op′ er•a•tive play –n. children truly join forces to achieve a common goal; they act as a pair or group, dividing their labor and coordinating their activities in a meaningful way

par′ al•lel co•op′ er•a•tive play –n. when your older brothers won’t let you be the bigger-than-life-sized monster that destroys their troopers so you enlist your little brother and mimic the play of the older two, on the other side of the room, in ‘real life’

just listening
you could have imagined they were playing all together

tho’ the lingo in one pair
was definitely more aptly used
than in the other