Desktop mode user here:
So I found out how to raise submission. On the left panel of the stats screen (the one that shows Arousal, fear, health and whatnot), there are certain acts that the "hero" likes. It seems to be randomly generated, but one of my custom characters likes getting tickled and getting cum on her body. So I tickled the character and the submission skyrocketed to 100%
What 100% submission actually means, I have no fucking clue. Nothing really changed asides from maybe heavier breathing from the woman. Might've been explained in the tutorial section, but who actually uses the resource that teaches you how to play the game?
BTW, if you hold down the left mouse button while holding any paddle, the dude winds up his attack and smacks the woman harder, leaving marks on the body based on which paddle you chose.