Shawn and his famous friends

Camila Cabello 

This singer is known by the song "Havana".

In 2015 she recorded with Shawn song "I Know What You Did Last Summer" which is on his first album.

Shawn and Camila are big friends, they're writing and calling to each other.

Niall Horan

He sang in a band named "One Direction".
He is known by song "Slow Hands".
Shawn and Niall are planning collaboration, but like Shawn told in one interview:

"We're really good friends and we hang out all the time, and we are always like, 'We should write a song,' and then we're planning on writing a song -- and then we just end up hanging out!"

Charlie Puth

His the most famous song is "I'm Only One Call Away" or "See You Again".

He performed on Shawn's world tour "Illuminate"

They spend together a lot of time, and often post funny pictures from this meetings.