[Nanya01]

It was mentioned in the StrikerS sound stages that Hayate wanted to grope Subaru, Teana and Caro was just about the right age to start groping.

Then Arisa was like 'you're still fondling other girl's boobs still?'

Hayate: Only to those who don't complain. I've been felt up too, you know. Besides, I think it helped everyone develop a healthy chest.

Of course, later in that same sound stage, Caro dragged Erio into the girl's side of the bath and then Subaru yanked off Teana's towel so Erio could get a good look at a naked girl (Teana).