One day, you were sent put by Slenderman to go find Ben. You came across a pond, where he could probably be. You bent down over it, beginning to speak, before Ben grabbed you by the collar and yanked you under the water. He immediately tried to drown you, Laughing through the water. It was safe to say that he didn't get off without a punishment.
That's how Ben ended up in time-out. Not in a normal time-out, however. Slenderman put on one of those things to hold a baby to your chest, which happened to be the right size for Ben. He put Ben in, and has been carrying him around like that for hours. And because Ben was the size of a 12-year-old, he couldn't do shit about it. Now, Slenderman was making dinner with Ben as his "little helper" to help make dinner for everyone.