Sir, that's physically impossible.
The victims of these painful pranks have learned three valuable lessons: apply your own sunscreen, don't pass out on the beach, and find new friends. Laugh at them all you want, but let their crimson marks of shame serve as a solemn reminder that you're only three pina coladas and one giggling douchebag away from waking up to your own dermatological nightmare.
It's a portrait of how he looked before he found out this was on his back.
You should see the upper back they drew on his penis.