Bolt was caught up in cheating rumors after he met Jady Duarte at Boate All In nightclub in Rio de Janeiro, Brazil on Saturday night.
The 20-year-old student sent intimate pictures of the couple to a closed WhatsApp group, but the photos quickly found their way into the public domain and onto extra.globo.com.
Now, people are swarming to Kasi's Instagram account and posting messages of support amid the cheating rumors.
One user commented on this photo,
Omg. How could he cheat on you again and again???? Kick him and find someone better!!!!! You don't need this loverat.
I CAN'T BELIEVE THAT BITCH CHEATED ON YOU YOU'RE A FUCKING GODDESS.
Neither Bolt nor Kasi have publicly addressed the Rio pictures yet.
The sprinter appeared to completely ignore the situation by posting a response to Prince Harry who wished him happy birthday and challenged him to a race on Twitter.
Bolt has reportedly been dating the 26-year-old for two years.
Throughout the 2016 Rio Olympics, Kasi's social media feeds were filled with support for Bolt.
What did I say?! My Boss did that! #TeamBolt pic.twitter.com/iSpqeBuqoc — Kasi B. (@kasi__b) August 19, 2016
Way before the cheating rumors were making headlines, people were already pointing out how beautiful Kasi is.
She has a huge following on Instagram, where many users lust over her looks.
Meanwhile, Jady Duarte spoke out after the photos she sent to her friends were leaked.
According to extra.globo.com, she said,
It's very negative. I never wanted to be famous, I'm dying of shame.
Jady told the website she was approached by Bolt's security and at first had no idea whom he was.
She didn't reveal details about the encounter, but described it as "normal."
It was not a big deal. It was normal.
But, she wasn't the only woman who caught Bolt's eye.
Videos emerged showing the athlete grinding up against a different woman at the same club.
Bolt was out celebrating his 30th birthday.
Elite Daily has contacted Usain Bolt's representatives for comment.