Teddi Mellencamp's father John Mellencamp raises eyebrows with social media post

Some of John Mellencamp's fans couldn't help but mention her daughter's surgery in the comments section of his latest Instagram post related to his music.

Teddi Mellencamp on Wednesday posted to Instagram that doctors had found "multiple tumors" on her brain and rushed her into emergency surgery within hours.

She  said in her post that she had been experiencing "severe and debilitating" headaches for the last several weeks. "Yesterday," she wrote, "the pain was unbearable and required hospitalization."

Her father, however, did not mention the health scare revealed by Teddi.

"Do you understand that your daughter's melanoma has spread and she will not live six months? Can you go and be a good father for once? She surely needs one," said a fan in the comments section of John Mellencamp.

Although Teddi and John have experienced periods of estrangement, their relationship has significantly improved over the time.

When Teddi was a teenager, she mentioned on her podcast "Two Ts in a Pod" that she didn't speak to her father for three years due to an argument over money. This estrangement was also influenced by John's divorce from Teddi's mother, Victoria Granucci, which impacted their relationship when Teddi was younger. 

John has shown his affection and support for Teddi in various public ways. John has been seen spending time with Teddi's children, showing his involvement in family life. Teddi has described her father as "so much fun" with her kids, who affectionately call him "Peepaw."

He, however, has never been a fan of "The Real Housewives of Beverly Hills," where his daughter starred for three seasons.