Custom idea:

1) Igor does need to get on his knees and straddle her thighs so that he can be in a position to push right and left punch into Penelope soft belly many times. Penelope utter erotic sounds as the punches collapse her belly. The action is to be filmed completely from the side (profile) so the depth of the pushes can be see.

2) The second part Penelope straddling the Master while he lies on their back and he sink punches into her relaxed belly. Again she is very aroused by the punches.

Look at 40 seconds of this clip on "Click for preview"