Who is the first pair to perform

The sisters.

Ami and Annie were definitely the toughest act to follow. So John figured they deserved a shot. The scarlet haired siblings were both walking together, identical twisted grins on their faces. They had gotten the **** bug before John had even touched them but now they understood the rules. At the end of every round the winner got to change 3 things about either themselves or another team, it was a race to see who could be the most depraved. The twins drew doujinshi, John was certain they'd be helpful devils for his shoulders.

"We can try," said Annie, adjusting her large owl like spectacles.
"But we need a cock," purred her sister. Both girls were pretty flat by John's standards, but they were always pretty nice when they came in to buy figures so John thought he'd give them a hand.

"OK then," he remarked spanking Anna I'll be a generous host and give you girls one change on the house," he remarked grinning as the two anime nerds both groaned in unison with his snapping fingers. The transformation was quite fast. Ami tearing off her jeans and panties in union with her fire red twin. The sisters gasped as their clits began to swell and change growing larger and thicker as they both became fully functional futanari. Before Ami could even comment her sister was on her knees, wrapping the 8 inch shaft between her A cups eagerly.