Credit: Splash News Online

Family fiesta!

One day after Kourtney Kardashian kicked off the new year in Miami, the E! reality star and her boyfriend Scott Disick, 27, spent some quality time with their son Mason at a private property near Cancun, Mexico.

"Kourtney and Scott seemed very relaxed," an insider tells the new issue of Us Weekly (on stands now).

Clad in an itsy-bitsy string bikini, a super-fit Kardashian, 31, sipped on fruity cocktails by the pool as her longtime beau soaked up the sun while playing with Mason, 13 months. According to an insider, "Scott seemed to enjoy the father-son bonding time" during the drama-free, three-day getaway.

The sunny vacation shows signs of progress for the couple, whose heated arguments were heavily featured on both Kourtney and Khloe Take Miami and Keeping Up With the Kardashians.

"In every relationship, you don't grow unless you go through some hard times," Kardashian explains of her on-and-off love, whom she began dating in 2006. "Growing and learning together has been the biggest change."