I have a training partner who has the obnoxious habit of grabbing my wrists and pinning them to the floor whenever he's in my guard. He seems content to just nullify me and do nothing else. I can momentarily peel his hands off by opening my guard and bringing my knees up. But I'm not really able to do anything significant in the brief lapse that follows and we just end up in the same position again. Ideally I'd like to break his posture down by grabbing the back of his head, pulling him down, and then going for a kimura,elevator sweep,or guillotine. Any ideas?