The man whose facial expressions behind President Trump at his Montana rally this week went viral says the Secret Service treated him well but told him "not to come back" when he was removed from his seat behind the president Thursday.

Tyler Linfesty, more commonly known to the internet as "plaid shirt guy," says Trump campaign staffers asked him and his friends to leave midway through the president's speech.

The Secret Service spoke to him for about 10 minutes and then told him to leave the rally, according to Linfesty.

"They treated me fine," he told the Billings Gazette. "They just told me not to come back."

Linfesty, who says he supports the Democratic Socialists of America and not Trump, told CNN he was determined to give his genuine reactions to the speech when he found out he was going to be behind Trump.

"I think I know why they removed me. It's because, well before the rally they told us that 'you have to be enthusiastic, you have to be clapping, you have to be cheering for Donald Trump,' and I wasn't doing that because I wasn't enthusiastic, I wasn't happy with what he was saying," he told CNN.

"The woman, she came in and she just said, 'I'm going to replace you.' I just walked off, I knew I was getting out for not being enthusiastic enough, but I decided not to fight it," he added.

"Each time I see one of these rallies, I see people behind Donald Trump clapping and cheering and being super enthusiastic, and I've always wondered myself, 'Are those people really being genuine?' So when I got back there, I knew that I was going to be genuine. I was going to give my actual reactions to the things he said. So whenever I disagreed with him, you could tell that I disagreed. But whenever I agreed with him, I clapped as well," he said.

Linfesty went viral on social media after Twitter and Facebook users posted video of his reactions to different parts of Trump's speech.

For instance, when Trump said "we've picked up a lot of support," Linfesty appears to mouth the words "have you?"