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