Yea remember that Max, being more military personnel than traditional superheroine, has explicitly demonstrated a very real capacity and inclination to escalate faster then he can possibly gain power now that she knows his tricks. And he KNOWS this, I'm not saying he will never escape ever again but it certainly won't be during one of these sparring sessions bar a serious effort of Deus or some other massive threat of a character for whom Kevin would almost be a side show.
Also for anyone curious about the movie he mentions, it's Five Deadly Venoms a classic Shaw Brothers film absolutely worth checking out for anyone remotely interested in martial arts movies and easily Shaw Brother's second best film.