Shawn Mendes Jokingly Called John Mayer An "Old Man" On Instagram

Shawn Mendes and John Mayer have many things in common. They both play guitar really well, they can both sing very well, and they are both adorable, etc. You could even go so far as to say that Shawn is like a mini John, as he's half of Mayer's age -- something the 19-year-old is not letting him forget!

On Instagram, John recently posted a throwback photo of himself from 1998, when he was 21 years old (only two years older than Shawn is now). In the picture, Mayer is holding on to a guitar in front of him, and wrote, "#tbt 1998. In it for life."

Shawn saw this as an opportunity to playfully poke fun at one of his idols, noting that 1998 was the year he was born, and wrote, "Year i was born old man @johnmayer."

John's response was also via good ol' IG, and posted a black and white picture of Shawn playing the piano, writing along with it, "🎹 @shawnmendes 📷 ya boy."

Shawn kind of looks like John here...

All's well in an Instagram war of good fun. Shawn and John are friends, and have even performed together. Last year, Shawn joined John on stage during his show in Toronto, and performed a mashup of two of their hits, Mendes's "Mercy" and Mayer's "In Your Atmosphere."

After the show, John had called the on-stage surprise "over the top good" and Shawn tweeted, "Damn. John Mayer is the best. My job is the best. U guys are the best. What an insane night."

Nice little bromance.

Photos: Getty Images