Kristin Cavallari's New Boyfriend Mark Estes Bonding with Son

Kristin Cavallari and her boyfriend Mark Estes are clearly pretty serious … ’cause not only has she introduced him to her kids — but it seems they’ve got a rapport!

The mother-of-three shared a picture to Instagram Sunday featuring her new 24-year-old beau with one of her kids … and they seem deep in conversation while Mama Cavallari is able to hang back a few steps.

KC didn’t add anything in the way of words to the pic … but she did drop a white heart emoji on the photo — so clearly she’s pretty happy with the chummy bonding going on.

BTW … unclear which of Kristin’s three sons this is — but, ya gotta imagine she introduced Mark to them at or around the same time, and it was long enough ago that one of her kids can seemingly hold a convo with him comfortably.

It seems like things are movin’ along quickly between these two … remember, Cavallari only revealed they were dating at the end of February — so things have seemingly progressed quickly between the two.

It makes sense when you consider it seems almost like fate was pushing these two together … Kristin recently revealed on her ‘Let’s Be Honest’ podcast that she first spotted Mark on TikTok with his crew The Montana Boyz.

Weeks after spotting the hottie, Kristin got a DM from one of the guys. She invited the group on her podcast, hit it off with Estes and they started seeing each other. Talk about a 21st century fairytale!