Serena Williams sparked a strong reaction with a new picture she shared with her social media followers at the weekend.Taking to Instagram on Sunday, the tennis champion posted a photo that showed her in a hot tub.MORE: Serena Williams gets fans talking in an unexpected neon look for springThe glamorous star could be seen at the far end of the tub, wearing a hot pink swimsuit as she covered her mouth with her hands.Serena's husband, tech entrepreneur Alexis Ohanian, faced her with his back to