Ken was not expecting such a detailed or heartfelt plan in response to him admitting his concern. Frankly, he's impressed and touched.

"Madoka-chan...."

But it's a disservice to her to just remain basking in the glow of someone saying things like that to him. He focuses on the conversation. "I'd like that. There must be many things only we can do."

"You can ride me," Leafmon offers. With no context. As a talking head with a pacifier.

This is obviously the best plan.