A 17-year-old girl from California shared a picture on Twitter last week of her dad staying by her mam's side while she undergoes treatment for cancer.

Her mam had to be isolated, and from it came one of most heart-warming and sweetest things you'll ever see.

The teen, McKenna, spoke to Buzzfeed and told them that her mam was diagnosed with thyroid cancer last October, and during her treatment last week, she was isolated in her room.

And her dad stayed as close to her mam as he possibly could.

McKenna's picture, which shows her dad sitting outside her mam's bedroom door, has gained nearly 3,000 likes since she posted it, and the Internet is exploding over the love her dad has for his wife.

McKenna told Buzzfeed: "The amount of love I've received is crazy and I didn't expect any of it, but I'm so grateful."

Her mam added: "Jon goes to every doctor's appointment, every blood test, every surgery, every radiation. And, as you can see, if he can't be by my side he is as close as he can get!"