Adult novel about a college guy who is the main character and he stops talking to I guess not say the wrong thing and he communicates with his friends by writing on sticky notes

[Reagan]

The book starts off with a college guy who is the main character and he stops talking to people verbally to I guess not say the wrong thing and he communicates with his friends by writing on sticky notes and he has a crush on this girl and they both prank call people one day using a phone book and his crush ended up finding somebody from the prank call and going on a date with him. Also him and his friends measured their d!ck sizes in a closet. Been trying to find this book for the last few years . Ik the cover was like green and black .

[Becca]

I Can't Tell You by Hillary Frank?

[Kris]

Becca's suggestion of I Can't Tell You by Hillary Frank sounds like your book.

Google Books preview: https://books.google.com/books?id=jfd...
There are different cover images.