"The worst day. My heart is broken," the devastated mum captioned the video. "Please raise your littlies to be kind."
"This weekend we had a drive by party for my son who turned five," she explained in the video.
"Do you want to know how many people came? One," she continued. "Normally, this would be bad for any kid, but my son has Down syndrome.
"My son has Down syndrome, and when he didn't realise what was going on, that hurt."
The worst day. My heart is broken. Please raise your littles to be kind.♬ original sound - nosilla865
"But what happens when he knows?" the woman continued through tears. "What happens when he knows that he's purposely being left out?"
The mum ended the video asking users, "why?"
Many people have forced to hold 'drive-by parties' due to coronavirus restrictions for gatherings and events. It involves guests driving past the house sometimes dropping off gifts and well wishes.
The mum couldn't hold back her tears. Photo: TiKTok
The TikTok clip has over two million likes and 68 thousand comments, with people offering sympathetic words to the teary mum.
"OK that's it we need a TikTok live bday for him," one user declared.
"Make a PO Box. We will send stuff!"
"Down syndrome or not, we are all the same, we are all beautiful and stay strong because we stand," said another.
"Happy birthday, don't cry he is a strong boy he don't need fake friends."r.
"It breaks my heart when people don't consider others," wrote another TikTok user. "Tell your little guy happy birthday from me!"