She wants a baby

Once they returned to their castle, the Queen had Bowser alone in their chamber.

"So what is it, my sweet?" Bowser asked his queen concerned.

The Queen smirked at him. "I think it's time we have a baby."

Bowser blushed heavily at that. "Really?!"

"I know you have kids already but I want one of my own. I want to show proof of our love as well as give Junior a younger sibling to be with."

"He and the others do tend to fight a lot."

"Junior is a good kid and maybe having a younger sibling to watch over will help him to become more responsible."

"That would be good. To be honest, I thought you were just wanting a baby cause you were badly wanting my dick."

The queen goes up to him seductively. "I didn't say that wasn't one of the reasons. How about we plan this baby making?"

Bowser blushed and smiled as he nodded.

They discussed about when and how they would plan this night. Bowser went to Kammy to check if she was capable of getting pregnant from him. She was but any babies would come out as eggs and most likely hatch into koopas. He was sure she would not mind. Kammy also gave her a potion she whipped up that will guarantee a pregnancy. They also planned to have Junior spend the night at one of his sibling's forts. The night was set.