As he stared, he felt his penis pushing out, pressing against Alice's private bits. Pushing the inappropriate urges away, Jeff decided to inform Max on what just happened, but didn't want to give away how he knew. He thought on how to word it, before ending with "Well, uhh, it seems that you're a girl now, Max."
Max looked back at Jeff, a slight blush over her face. "What do you mean? How did this happen?" "Well, I don't really know.. Uhh, well this is interesting." Jeff picked Max up, bringing her to his bed. "Well, I mean... I guess you've got these areas now."
Max looked embarrassed, trying to hide the new parts. "But I don't wanna be a girl! I don't wanna be like Alice!" Jeff sat down next to her, remembering that Alice was still in the diaper he was wearing. "Well, I mean... Wait. You could get closer to Alice like this, though."
Max looked at him, confused. "But what do you mean? How would this..." He pulled Alice out, laying her down on the bed next to Max. "I mean this more in a literal sense. This may feel weird, but just hold still for a moment..."
He turned Max to have her legs on the bed, spreading them apart. He then moved Alice's head closer to that area. Max stared at Jeff, still confused. "But how would this change anything?"
To answer Max's question, he pushed Alice forward, her head spreading Max's labia apart and going in. Max tried to back up, but Jeff reached forwards and pulled her closer, sending Alice further inside. "Jeff, this feels weird..." "I'm sure it does, Max."
He brought Max against him, leaving Alice mostly inside now. He lowered her down onto her back, and saw which hole Alice went into. "You might feel pain, or this might feel nice. I really can't say before doing it."
He put his hand and pushed into her vaginal opening, Max screaming as he did so; He couldn't tell which one it was. He reached further, pushing Alice further in, until she was fully inside Max's womb. "Alright, and done."
Pulling his hand out, Max's belly was bloated; It was obvious that something was in there. Jeff put Max back on the ground, and his belly was entirely covering his lower area. "Well, you don't need to be as worried about someone seeing it." Max was still clearly embarrassed, though, at even the thought.
"Hold on, Be right back." Jeff left the room quickly, heading down to Alice's room. Taking off her stretched diaper, he put his own lower clothes back on, before picking up a pair of clothes on the ground. He brought them back to Max, so she could get dressed.
Upon entering, he walked over to his now-sister. "Alright, this may make it a bit easier on you." He started to help her get dressed in...