In the interview with The Sunday Times, of London, Collins revealed that he's held a grudge against McCartney since a 2002 conversation when he felt the former Beatle was condescending to him.
After the interview was published, the former Genesis singer/drummer reported that McCartney contacted him via email about the alleged slight.
"He was upset," Collins told Billboard. "I certainly didn't get any flowers from him; I got more of a 'Let's just get on with our lives.'"
But Collins doesn't have much sympathy for McCartney's recent reaction, he told Billboard.
"I'm sorry he's upset that I kinda said something nasty about him," Collins said. "Well, it wasn't really nasty. If people don't tell people that sometimes their attitude could be a bit better, then you're not gonna get any better, y'know?"
In the interview with the Sunday Times that triggered the exchange, Collins claimed that when he asked McCartney to sign a copy of a Beatles book at an event, the rock legend mocked him.
Collins said McCartney turned to his then-wife Heather Mills and said, "Oh Heather, our little Phil's a bit of a Beatles fan." After McCartney made the alleged statement, Collins said he thought, "You f***, you f***," and added he "never forgot it."
He also told the paper that McCartney "has this thing when he's talking to you, where he makes you feel ... 'I know this must be hard for you, because I'm a Beatle. I'm Paul McCartney and it must be very hard for you to actually be holding a conversation with me.'"
After interview and McCartney's contact, Collins told Billboard, "I think maybe I should just brush it under the carpet and forget about it and move on, but it did happen."