Your heart quickly picks up pace as you now know what your fate will be. You try to take off your shirt but you look at your hand, black pads forming and claws extending out as you place your feet back and sit on your haunches, getting ready for what is to come.
You watch as your face pushes outward, blocking some view, your nose turning black as everything in the room looks sharper. Your girlfriend lifts her tail and is bellowing to you to mount her. Your arms increase in size, you feel your whole body pick up weight from your growing muscle mass. Your shirt begins to rip as tawny fur beings to spread all over your body, your hair lengthening and growing poofy, thick, and spreading down your chest. You try to scream but all that comes out is a thundering roar.
You start to feel something churning down at your crotch as you watch your human cock reform and become thick with barbs, a sheath covering the base as you new lionhood throbs. You slide your way over to your girlfriend, putting your half formed lion body over her and begin to thrust. You finally meet her and you slam your thick lion cock into her folds. She roars in pleasure as your rump becomes heavy with muscle, fur spreading over your butt as you feel your long, thick tail push its way out. You keep thrusting as you fully change into a full grown lion. You feel your seed churn as you bite down on your mates neck, biting hard your feel your seed shoot out into her, holding your tail high and proud, mating like the big lion you are.