Here is the full list of all 50 Lust Theory - there are Season 1 achievements.
Blackmailed Nicole twice
Acquired all the other achievements
Smashed the clock
Found out about cellulite from Elizabeth
Made Zoe cry
Spied on Zoe playing
Spied on Megan changing
Found the secret photos on Nicole's phone
Told Nicole the truth about Ellie's gun
Asked Ellie to **** ****
Ignored Ellie
Walked home with Zoe after school
Sat through the whole main menu video
Used the Gallery
Finished the main story
Finished the "perfect" day
Finished the "NFG day" 4
Finished the "NFG day" 3
Finished "Freeze day"
Experienced the first "Lust Time"
Was left naked in the School hallway
Got enough experience for Ellie's game
Got impaled by Jessica's heel
Hit Taylor with the ball
Finished the "NFG day" 2
Finished the "NFG day" 1
Touched Sophie without asking
Reset the day with all the girl's stories active
Spied on Zoe in the girl's locker
Told nicole not to assume your gender
Spied on Megan showering
Told Ellie you like trains
Blocked the ball
Clicked on the "Whatever" poster
Clicked on Zoe's house enough times
Barged into Megan's room
Got to "Free roam mode"
Tried going into Megan's room at night
Ratted Jessica out about her date
Found all 4 interactions before Elizabeth came home
Used a certain little red button
Used the Hints button in free roam
Chose all the correct answers on the pop quiz
Found EVERYTHING
Used the fast-forward button to reset the day
Used the "Angle button" once
Finshed the intro with Nadia
Names all the relationships
Used the "Panic button" once
Checked out the "About" screen in the menu