You take one for the team.

After everyone is untangled, you take a look around. Amy's breasts sure are huge now, and yours are looking like D's, maybe, with nipples as big as your thumb. Your bulge in the middle is sure obvious now, and Amy's is twice your size. Your butt maintains its size advantage, probably due to the work everyone has been putting into it. Your hips are even looking fuller, and the thong is getting tight, so you remove it.
"It was getting too tight for my sexy butt," you tell Amy after which you stick your tongue out at her.
"How do you want it, owner of the sexy butt?" Blue asks while holding her throbbing and leaking massive blue cock in her hands.
"Uhm," you pause, looking at its size. That is rather large.
"Amy, how should I take it?"
"Ride her," Amy commands. Blue sits on the couch. Her cock reaches up to her own mouth as she holds it straight up.
"That is going to like damage my insides...won't it Red?"
"No Master, of course not. Demon cocks cause you to stretch in the right way...if you are good enough, that is. Otherwise it will tear you up inside. But I know you are good enough, just take it slow, and think stretchy thoughts." Red pats you on the butt.
"Facing her?" You ask as you clamber up and stand in front of her.
"Oh, yes. I want to see this." Red and Amy sit to either side.
"Ready?" Blue asks with a broad sexy smile, drawing your gaze to where you and her are about to couple. You jump a bit as her cock touches your butt; you didn't realize you had gotten into position already. Two sets of hands on your cheeks spread you wide. Your cock pokes Blue's face. You are leaving wetness and you didn't even realize you were so hard.
"Just like that," Blue encourages you. "You are so loose already! I'm most of the way in!"
"Well I did take all of your hands pulling at me for a while. I just need a little more."
"Amy look at that!"
"I see, it's almost in!"
"I can feel the pressure! I'm thinking stretchy thoughts! Is it working?"
"Yes! That fat blue cock is sinking deeper! You are almost over the ridge!"
"I'm gonna push..."
"You got it, the head is in!"
You shimmy your butt a little. "Feels like there's not much room to spare. You can stop spreading my cheeks now."
"We haven't been since she first got past them," Amy slaps your butt to prove it.
"I feel spread wide still," you tell her.
"That's me," Blue tells you.
"Well, that's not so bad."
"Just wish her cock had a big bulbous head, huh?"
"It's big enough, thanks," you quip. "So now I need to sit in your lap?"
"Yup, that's the deal."
"Do I get your cum too?"
"If you want."
"Sounds like a good goal, then." You let go of her shoulders and let yourself sink down. You manage just an inch or so at a time.
"Oh wow, it's like his butt is gobbling up my cock...! Shoot!"
"You are cumming...!?!"
"Her balls are pumping, yeah! Take that shemale demon cum, honeybuns!"
"I am, I am! It's filling me! Overfilling me! Now this is a good sized load of cum, I'm not afraid to say!"
After the cum stops, the cock in you shrinks and falls limp.
"That was disappointing. You were only in there a minute." Amy sounds displeased.