(This is takes place in a timeline in the future!). You, and Katsuki are now married, and you have a baby called Yuri, but she hasnt said her first word yet when one day...

Katsuki have left Mina to babysit his kid because you both were partnered up for a mission, but then his other friends came along because they insisted. Okay, they were gonna visit but they found out he was gonna be busy so they just joined with the babysitting thinking it would be fun. But while you and Katsuki are away...the baby's first word was said. But it was the flippin f-word!

Soon, Katsuki arrived holding the baby. When he found out Yuri said something bad he held it up infront of the group "Now which one of you morons taught her to cuss?!" He exclaimed.

Sero then spoke in a sarcastic tone "Yeah, I wonder who..." he said, rolling his eyes, already knowing why the kid was like that, and it is absolutely no surprise tbh as Mina commentted, "Heh, we all know whose responsible for this".

In reality, it was Katsuki who have influenced his own child, but yeah.