On Saturday, Justin posted a vintage picture of the couple leaning up against a Rolls Royce.
"@drewhouse#diddyfordrewhouse @diddy KP YOU WILL ALWAYS BE REMEMBERED FOR THE STUNNING WOMAN YOU WERE INSIDE AND OUT.," Justin captioned the image.
Prior to Justin's post, Diddy posted the same image with him and Kim, who passed away last November of pneumonia.
"This picture will go down in history as the first time I said she was MINE!!!! AND THE FIRST TIME I TOLD HER I LOVE HER, little did I know I was hers," Diddy wrote. "Miss you BONNIE and will forever. Maaaaan life is beautiful to have had these experiences. Love you baby. @ladykp"
Fans immediately criticized the Biebs for using that image to promote his Drew House clothing line.
"Delete this sir he shared this picture in memory of his wife not for promo for the clothing line," one fan wrote.
Another said Justin's post was "disrespectful," arguing that Diddy was "mourning about his girlfriend" in his post.
Justin, though, shot back at his critics, saying, "Ur wrong. God knows my heart, I know them and their family. Don't tell me I'm being disrespectful. I have all of the respect for both of them."
He later added, "I didn't realize it was a photo of [Diddy] mourning KP, but I totally respect that, but I also respect how sick of a photo that is! It's allay [sic] to appreciate art. Photographs are art and he happens to be wearing an identical outfit of my clothing line and I thought it was really cool."
Diddy has not publicly responded to Justin using the picture.