pop the bean
This refers to an act performed on a male horse as part of groomming, when a lump of smegma that has built up under the foreskin and beneath the glans is popped out manually by the stallion's groom, vet or caretaker.
Hey Bobby!, give Secretariat a complete and thorough grooming today, and make sure you pop the bean on him!
pop a bean
to take an x pill
Let's pop a bean before we go to the rave tonight
Popping a bean
Taking a prescription drug, such as ecstasy, molly etc.
Hey im popping a bean, it's gonna be lit!