Russell Simmons Not Fazed Over Daughter Aoki Dating Much Older Restaurateur

Russell Simmons and Kimora Lee Simmons' 21-year-old daughter is dating a 65-year-old guy -- with whom she's on vacation right now -- but Papa Bear isn't trippin', or so it seems.

The Def Jam co-founder tells TMZ he spoke with his daughter, Aoki, a day before the news came out she was romantically involved with Vittorio Assaf -- the founder of Serafina Restaurant Group -- which came to light last week through PDA-filled vacay photos of them.

The couple is out in St. Barts right now -- and shots of them smooching have gone viral ... not to mention invoking the wrath of social media, but Russell says he's not stressing it.

He tells us Aoki had told him this would be making the rounds on social media -- so Russ had a heads up, and he adds ... "I’m not gonna kick and scream about her choices."

RS goes on to say, "All I can do is offer my advice and unconditional love."

Russell had telegraphed this sentiment from an IG post he'd put up this past weekend ... in which he threw up a photo of him and Aoki together from Father's Day last year, where the two of them are posing and smiling together. He also attached a sweet, loving caption.

Safe to say, not everyone is as chill about this as Russ appears to be -- and they're letting him know about it in all his comments ... ditto for Kimora too, BTW, who's getting roasted.

Sounds like fans think the huge age gap is wildly inappropriate ... and social media warriors are blowing up Russ and Kimora -- plus, Aoki herself -- to let them know how they feel about it. As you can imagine, they're displeased with Aoki's dating choices, finding this creepy.

And yet, Aoki herself is tuning out the noise -- she's posted some IG Lives this weekend that appear to have addressed all the backlash ... and from the sounds of it, she doesn't care!

It's a bit unclear how exactly they met -- but word is, it was actually there on the island.

SRG hosts multiple Italian restaurant locations all throughout NYC ... including eateries for other types of food like pizza, sushi, French cuisine and more. Goes without saying, Assaf is loaded and then some.