Here is the full list of all 50 Lust Theory - there are Season 1 achievements.
Asked Ellie to **** ****
Acquired all the other achievements
Made Zoe cry
Ignored Ellie
Finished the "perfect" day
Finished the "NFG day" 4
Finished the "NFG day" 3
Was left naked in the School hallway
Found out about cellulite from Elizabeth
Finished the "NFG day" 2
Hit Taylor with the ball
Finished the "NFG day" 1
Spied on Zoe playing
Spied on Megan changing
Spied on Zoe in the girl's locker
Walked home with Zoe after school
Used the Gallery
Finished the main story
Experienced the first "Lust Time"
Blackmailed Nicole twice
Finished "Freeze day"
Smashed the clock
Got enough experience for Ellie's game
Got impaled by Jessica's heel
Touched Sophie without asking
Told Nicole the truth about Ellie's gun
Told Ellie you like trains
Clicked on Zoe's house enough times
Reset the day with all the girl's stories active
Found the secret photos on Nicole's phone
Told nicole not to assume your gender
Spied on Megan showering
Blocked the ball
Clicked on the "Whatever" poster
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
Sat through the whole main menu video
Checked out the "About" screen in the menu