John Mayer once gave Jessica Simpson his own concert DVD as a birthday present, it's claimed.

Apparently, the serial celeb-dater thought the footage of himself performing would be an appropriate gift because he was unable to attend his then-girlfriend's celebrations in person.

"Several years ago when he was dating Jessica Simpson, he couldn't go to her birthday party because he was on tour," an insider tells Page Six.

"So the night of her birthday she had dinner with [hairdresser] Ken Paves and a few friends. Everyone thought John would forget her birthday, but then a gift arrived from him -- it was a DVD of him in concert.

“Jessica spent the rest of the night watching the DVD on a loop, 'being with him.' It was so sad."

'Sad' doesn't even begin to cover it...

Remembering John 'n' Jen