Possess her by going up her ass

You then lunge forward straight into Ava's ass. she starts moaning and uses the box for support. You make your way up her ass. First your arms enter her butthole, then your head, then your torso, legs, and finally your feet, then you and Ava both lose consciousness. Your vision then returns a few seconds later, you get up and immediately notice that you are wearing a tight shirt and you now have B cup breasts. Excitedly, you run to the body length mirror in the corner of the room.

"Wow!" you say as you saw Ava in the mirror. Lifting up your black painted fingernail hands, you begin violently groping and squeezing your breasts through her tight graphic t-shirt. "Hmm, these feel good" You mused, enjoying the sound of Ava's voice leaving your lips. Then you move your hands to Ava's massive booty. Squeezing and grabbing it through her leggings which felt amazing. You then swiftly take off her leggings and panties and turn around to admire her thick ass in the mirror. "Damn Ava! Now this is an ass to die for" you say still rubbing your new ass.