Flea and his band mates are known for performing wearing little more than a sock to cover their genitals and the photo is quite ambiguous, leading many to believe Jason had his daughter Lola, 9, pose with an unclothed star.
Momoa, best known for playing GoT character Khal Drogo, admitted to being a total fan boy about being allowed backstage at the Chilli Peppers gig and that there were perks to his legendary Khal Drogo status, as he posted the photo on his prideofgypsies Instagram account which has nearly 2 million followers.
The post attracted some attention from people both admiring the photo and Lola meeting the renowned showman, and those who questioned Jason's parenting.
Instagram user super_wallie_bruh said, "Is he wearing pants? I HOPE so," with irina_chap commenting along similar lines, "A man with a guitar is naked? With a little girl?"
One particularly upset fan typed, "I'd like to understand why, as a father, did you post such picture. Flea or not Flea, is still a naked adult next to your daughter. Is it normal for you? Is it a common practice in your family? Disappointed!"
Others were more forgiving, with therealmacready saying, "Flea is always naked (except for a sock), why is everyone surprised?"
"Pretty inappropriate IMO. But hey, it's just my opinion, and they're free to parent as they see fit!" said lieselann.
Another said, "I don't see the issue! Nudity is the natural human form!! They have nude beaches! The kid doesn't seem freaked out and his junk is covered, and "Even if Flea was naked, he has a guitar over it. Calm down people. You get offended over anything."
Some had a closer look at the photo and say that Flea is obviously wearing black briefs and has his phone in his hand - two things that look as though they may just be an extension of the black guitar strap and the definite source of confusion.
Jason hasn't commented on the uproar and went on to post more photos of his children at the Chilli Peppers gig at the Staples Centre in Los Angeles on March 7.