If you don't know who Shawn Mendes is, you're either too old or you don't listen to daytime radio.
The 18-year-old Canadian pop star is best known for his song 'Stitches' and is following in the footsteps of his fellow Canuck Justin Bieber in terms of album sales and a global fanbase.
And, as Ed Sheeran has learned, there's no better way to expand upon that global fanbase than by turning up to play at a wedding and the subsequent video going viral.
In fairness to Mendes, the video below is of him playing at two of his friends' wedding, and he did sing an original song written for the occasion - 'Try My Best' - which was based on a love letter written by the groom to his bride. Awwww.
Watch it below: