You've gotta hand it to Kelly Osbourne, she's knew exactly how funny her "epic" Instagram fail was and didn't back down.

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On April 16, Kelly posted a photo of herself in the pool with her sister-in-law Lisa Stelly. The shot was supposed to give her 2.2 million Instagram followers a bit of life envy while showing off the ladies' impressive bodies.

"#SisterSunday #DivaLife with my sis @mrslisao #BestPoolDayEver πŸ˜‚πŸ’œ," she said.

Quickly though, people noticed a strange thing behind Kelly. There appeared to be a baby's arm in an inflatable floaty. From the juxtaposition of the image it almost looked like Kelly's arm.

"I never noticed your tiny left arm before!," one person joked. Anther asked, "WHY IS YOUR HAND SO SMALL?" Another added, "Whoa. Is that not a baby arm/hand over your friends left shoulder? It cannot be your hand!!!"

The former reality TV star got a kick out of photo fail and reposted the shot, this time with a red circle and an arrow pointing to the random body part.

"Check out my sexy baby arm!The most hysterical yet #epic #PhotoFail!," she wrote. "This is instant karma For trying to hide my fat a-- behind Lisa while holding my niece! 😩"

The arm is likely that of Jack Osbourne and Lisa's 22-month-old daughter Andy Rose, but it's way more fun to believe that it's Kelly's.