The Michigan-Michigan State rivalry got heated early in the offseason this year.

When Spartans’ head coach Mark Dantonio was talking about his team getting snubbed by the Outback Bowl, he took a jab at Michigan, saying he would “continue to focus on beating Michigan.” That statement didn’t sit well with Jim Harbaugh.

Shortly after that comment, Harbaugh fired off a tweet slamming Dantonio for the comment.

Not to be outdone, Dantonio fired off a tweet of his own in response.

For fans on both sides, this is what the rivalry is all about.

On Thursday, Harbaugh provided some insight as to way he got so upset about Dantonio’s statement and why he fired off the tweet. He said that he didn’t like how the Michigan State head coach dragged the Wolverines through the bowl frustration.

Harbaugh also said he’d prefer if Dantonio just not talk about Michigan.

Here’s the interview with Harbaugh expressing his frustration: