Can you not ever chat with your (step-) brother yet? Also, is 20 the current max on lust for your (step-)dad? Just wondering if I've reached the end of where you currently are at with the game or if I'm just missing the next step after several 6 packs and some viagra stuff I can't figure out how to take lol
Chatting is just there for easy affection gain, if you want to lower the affection, you need to proposition them while the lust is still low & they haven't engaged in any acts with you yet. This comes with a suspicion cost though, hate fucking is not easy business.
Well if the lust reaches 20, you should proceed to the next step - give him a handjob to get the ball rolling.
Because the time & sus cost vary for each tier of actions, there is a cap for the lust gained for them. So people can't just spam tease, for example, to get to the good ending & disrupt the narrative.
The viagra stuff still hasn't got an use yet. Sorry, just buy beers only for now.