Brown paid an emotional tribute on Twitter, posting the image of the two with his younger twin sisters Jessie James and D'Lila.
Brown, whose father is Al B. Sure, captioned the post with a string of broken heart emojis.
Brown’s post came hours after P Diddy broke his silence, telling fans he misses Porter “so much”.
Diddy, real name Sean Combs, dated the actress on and off from 1994 until they split for good in 2007. They have a 20-year-old son and 11-year-old twin daughters together.
Diddy said the days since her death have been a “nightmare” that he is struggling to “wake up out of”.
He shared an emotional montage of the couple, containing photos and video clips and wrote: “I don't know what I'm going to do without you baby. I miss you so much.
“Today I'm going to pay tribute to you, I'm going to try and find the words to explain our unexplainable relationship.
“We were more than best friends, we were more than soulmates. WE WERE SOME OTHER S***!! And I miss you so much. Super Black Love.”
Al B. Sure also shared a picture of himself with Porter, who he was married to from 1989 to 1990, alongside the caption: “#ForeverMyLady.”