The “Valentine’s Day video” was a private video Phil Lester made as a Valentine’s gift for Dan Howell in February 2010.

Phil uploaded it privately to his second channel, LessAmazingPhil, while Dan was on holiday in India.
The video features Phil sharing his favorite memories with Dan and expressing affection. It was reportedly intended as an April Fools’ prank to be made public on April 1, 2010, but they decided not to release it.

The video accidentally went public due to a YouTube glitch in September 2011, was seen by fans briefly, and then removed.
Neither Dan nor Phil were dating at that time, according to their statements, but it has been a long-discussed piece among fans, resurfacing especially after they officially confirmed their relationship years later