The act of splintering is when a man puts his penis in between a girls armpit and masturbates. Recent polls show that more and more teens are splintering. In a recent study, 68% of sexually active teens between the age 14-16 say they have splintered before.
ex. Dude, i was splintering Seth's mom last night and Seth walked in on us!
ex. Were you splintering with Alyssa after Homecoming, because I thought I heard you all in the bathroom?