Toddlers explore their own and each others' genitals.
They call this game "playing doctor", probably since at the doctor they've had routine examinations of their private parts.
Adults use the phrase as a "cutesy" way to say "sex".
"Man you look tired!"
"Yeah Robin and I were up all night playing doctor."
Buy a
playing doctor
mug!
Something drug dealers and poor people take advantage of but if anyone tried to cut it they would be immediately killed by someone on it.
"Today we are going to cut taxes and welfare by---"
*Stabbed by a guy who owns an Escalade, $10000 worth in diamonds and still gets welfare