Kristin Cavallari is going into detail about her split with Mark Estes, saying age was a factor while getting choked up at one point.

The 37-year-old reality star discussed why she broke up with 24-year-old Estes after dating for 7 months on Tuesday's episode of her "Let's Be Honest" podcast.

Kristin kicked things off by telling her listeners it had nothing to do with cheating or being mean, noting that Mark was always sweet and supportive.

She said Mark — co-creator of the "Montana Boyz" podcast — was her best boyfriend ever, but that just wasn't enough.

Kristin said Mark simply didn't have enough life experience because he's young and needs to find himself, adding that she was always aware of their age gap.

Suddenly, Kristin got a bit choked up as she described Mark as a "good guy" and their relationship as very healthy and mature despite his youth. She went on to say Mark would make "someone so happy one day" and "have a beautiful family of his own."

Kristin also confirmed what our sources told us last Friday ... their relationship was never intended to be long-term.

However, Kristin said she wants to remain friends with Mark and keep him in her life in some capacity.