Masturbating at night on the bed, you can raise lust from 1 to 5 (if lust is higher than 5, it will not rise)
Inspection scene at the beginning of the game +1 lust
Scene with Ethan in the Dining Room + 1 lust
Photo shoot +1 lust
Scene with medical examination +1 lust
1 nurse scene +2 lust
2 Nurse Scene +2 lust