1: do the mansion a ton and get one time done great (I didn't watch what my lewdness was)
2: in the sand town the temp place offers tea to help with lust after you leave it for a while as with all.
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No problem, I think there are other ways to do it as I was doing an run through of no lewding (aka pure run) and noticed that if you take the time in the early game to (sand cave and before) to power level a bit and don't sell any materials you are usually good for the entire run if you go straight for Matk which makes the game quite easy to avoid the annoyances of the sexual stuff. So I think there are other ways to get it down but I may have missed it throughout my go through as a result of not losing once, grinding hard early, searching hard and finally doing all the puzzles.