Some army game or other.

 

Must be just one moment taken from a full-length video. I'd guess that the starkers ones are being punished for - or having to do a forfeit for - not satisfactorily performing some commanded task, though the guy standing second from left looks as though his turn might be coming next. In my books being made to suck cock would count as more of a reward than a punishment, though of course I wouldn't show it, duly faking my reluctance as I inwardly felt the sheer pleasure of taking cock into my mouth.