Ok, it's quite obvious that Rainbow Dash, Pinkie Pie, and AppleJack are all friends with each other, but that is not the only other connection they share. What is that connection, you may ask? I'll tell you: they are all dating my son Noah. That's right: all three of them. That is why each of them have the same demon star pentagram on their bodies: one on AJ's tongue, one on Pinkie's belly, and one above Dashie's tail.
AJ, Dashie, & Pinkie (c) Hasbro, My Little Pony: Friendship is Magic, & Lauren Faust