In the afternoon inside of the large mansion with Shinji Ikari holding Rico in his arms, smiling to have his day with him, kissing his head gently as they go to the basement, looking for a helium tank for their giant blimp they're planning for today.

Rico: thank you for agreeing with me on this, Mommy Shinji. This is going to be a fun day.

Shinji: *chuckles* no problem, Rico. I can't say no to someone like you that's really adorable.

Rico: *smiles* thank you for the compliment. Now, let's set up helium tank in the living room.

Shinji: on it, dear.

He picks up the helium tank, carrying it out of the basement to the living room where they set it up in the middle of the room, putting the hose on the nozzle. Rico hangs on tight on his back, prepared for him to put the hose in his mouth to expand.

Shinji: are you ready for this, baby~?

Rico: yes, Mommy. I'm ready for you to start floating and being my blimpy boy~.

Shinji: hehe, good. I'm going to start inflating myself right now for you. Hang on tight~?

Rico: I would love you to be so big and floaty. Get as big as you can for me, Mommy Shinji~.

Shinji giggles, putting the hose in his mouth, turning on the helium tank as it starts to puff his cheeks up, expanding his belly slowly with his shirt stretching out, popping each button off that's flying everywhere as his butt and thighs expanding, stretching out his pants to make his butt crack exposed. Rico laugh to see the sight of his Best friend expanding more bigger, floating off the ground with his arms and legs expanding, raising upwards and his chest fully expanded. Shinji moans softly, spitting the hose out of his mouth, and finally becoming a big balloon for the day.

Shinji: *muffled* that feel so amazing, Rico. I'm so full and floaty like a blimp for you to play with~.

Rico: you really are, Mommy Shinji. You look so hot as a blimp, hehe~.

Shinji: *muffled* aww, thanks, baby. Wanna go float around and bounce on my body? I can be your bouncy castle~.

Rico: I would love you to be my bouncy castle. Let's do this~.

He gets on top of him, bouncing on his Inflated body like a trampoline, laughing to have fun with his ballooned best friend. Shinji giggles, enjoying the sensation of Rico bouncing on him which turns him on, having a noticable bulge through his pants. Rico notice it, hugging his inflated butt, making him moan softly as he would pull his pants down, putting his small penis in between his large cheeks, thrusting him slowly.

Rico: ohh, Mommy Shinji. You're so tight in there for my little peepee, it feels amazing. Your butt is so big and squishy, hehe~.

Shinji: *muffled panting* and you feel so amazing inside of me, baby. Keep going for your balloon Mommy~.

Rico: I'll keep going for you. Let me give you a stroke on your hard peepee down there~.

Shinji: *muffled* yes, baby. Stroke Mommy's hard peepee. I really need it so much~.

Rico reach down, giving his penis a good stroke while pounding his Inflated cheeks more. Shinji eyes rolled back in his head, enjoying him playing with his inflated body like this as he would then ejeculate all of his love on the floor, feeling his small member filling him up with his warmth. Rico giggles, cuddling on top of him, feeling him kissing his cheek after their taboo.

Shinji: *muffled* oh, Rico. You really made me feel so good. Thank you for this~.

Rico: you're welcome, Mommy Shinji. It was really fun having this day with you. You're my best balloon boy~.

Shinji: *muffled* aww, thanks, baby. That's so sweet of you. Wanna bounce on me more~? *Wink*

Rico: sure. I would love to bounce on you more, Mommy~.

He stands up and bounce on his Inflated body again, laughing to play with his Inflated best friend. Shinji giggles, looking up at him as he was really loving to be his giant, blimpy best friend and Mommy for their special day together. He thought about a lot of more things to do for them to even have a lot more fun, but decide to be a big blimp for today.