JustaOneGirl did a good job expanding on the strategy, but basically acting nice, compliant, and interested in Isaac as a person triggers his lust, so it should be used as last resort. It is possible to make it through dinner without going over the danger threshold, (thus surviving without using intimidate,pacify, or convince). Using a skill to survive going over the danger limit will lower his bar by 1 action and give you more 'wiggle' room or you have to balance him perfectly. if its a bit confusing i also recommend making as much use of the back button as you need.