It’s becoming incessant… he will lie on his front on the sofa with his hands over the top of his joggers and- for want of a better word- hump. To the point where he’s flushed and sweaty. We ask him to stop and to leave his willy alone but he just gets straight back to it. He’s been doing it for a while but it really ramped up since we started potty training him and he’s not in nappies during the day anymore. My eldest DS didn’t do this and we’re just not sure how to handle it- any suggestions?