Mix the cake mix, JELL-O, egg whites, oil and water in a mixing bowl. (Add green food coloring if you want the green to be brighter). Pour the mixture into your cupcake liners and cook for about 15 minutes.
While you wait, you can prepare the frosting. Mix the sugar and the butter and beat the mixture for about three minutes.
Add the whipping cream and the pink drink mix and beat the mixture together for about one minute.
Once your cupcakes have cooled, ice them and add chocolate chips to look like watermelon seeds.