When a girl wants to have a foursome with 3 guys, but she can't decide who to pleasure first. The 3 guys then proceed to stand up next to each other. The girl gets on her knees, then gives the middle man a blowjob, while she jacks off the other two. The in and out motion of her head and arms resemble a pteradactyl.
Tom: Jenny gave the pterodactyl to those 3 guys at the party!