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