Having gone out of his way to help raise his children in a gender stereotype-free household, a father from Massachusetts was appalled to discover that his five-year-old son was being bullied at kindergarten for wearing nail polish.

Over 30,000 retweets and 60,000 likes later, Aaron Gouveia had not only comforted his upset son, but also used Twitter to create a full-blown social media campaign against toxic masculinity.

Within hours of posting about the issue, the father and son were inundated with messages from men and boys – including a former player from the family’s favorite football team the New England Patriots – sharing pictures of themselves with painted nails in solidarity.

Tweeting under the handle @DaddyFiles, the name of his parenting blog, Gouveia’s thread began with a picture of his son wielding a fish and the words: “This is my son, Sam. He’s five. And today he learned how shitty and harmful #ToxicMasculinity is. My rage meter is spiking right now so excuse me if this is a little raw but there are some things I want to say about BS #gender norms (a thread).”

He continued: “Sam is my middle child & he’s a terror. A ‘boy’s boy’ as so many (not me) would say. He’s rough and tumble, he’s loud, he’s always dirty, loves trucks, plays sports and knee drops me from the couch. But he also loves a lot of ‘girl’ things.”

Perhaps appropriately, the thread ended with Gouveia’s own painted middle finger nail raised, praising his “beautiful polished boy”.

In response, Martellus Bennett, the former Patriots tight end, tweeted a photograph of himself painting his nails with his daughter, writing: “I rock pink nails all the time.”

Gouveia, 39, who works in public relations and lives with his wife Martha, 40, and their three children in Franklin, said they have been blown away by the response.

“I’m so incredibly moved by the number of people who’ve written to us,” he told the Guardian. “Normalising this [is the goal] and just changing a handful of minds.”

Sam, meanwhile, said the supportive tweets had “cheered me up” and given him confidence to keep decorating his nails with pride.

The gender-neutral parenting movement has gathered substantial momentum in recent years with the rise of non-gendered toys, “theybies” (parents who avoid gender pronouns altogether in an effort to avoid gender bias).

Gouveia said he does not blame the children who bullied his son, saying: “At this age, it’s learned. Usually this comes from the parents.” But he praised the kindergarten, which he said took the situation “very seriously”, using it as an opportunity to talk about acceptance with their students.