Lord Disick and Lionel Richie's 20-year-old daughter arrived to the massive yacht Thursday in Capri, Italy.
Already getting in on the action, 36-year-old Disick and Sofia were seen jumping off the side of the vessel, along with Kylie's new BFF, Anastasia Karanikolaou.
The couple and Anastasia were drinking wine and hanging out a lot together on the yacht.
At one point Scott and Sofia were seen wrestling on the back of the boat with the "Flip It Like Disick" star eventually pushing his smoking hot girlfriend in the water.
Sofia and Anastasia also got in on the water sports, and took out the yacht's wave runners for a ride before plunging into the water again.
The birthday girl has been enjoying herself, and was seen heading into town on a dingy with her man, Travis Scott by her side.
Kourtney Kardashian is also in Italy with the kids.
The mother of three is expected to meet up with her "KUWTK" family for Kylie's birthday festivities.
Scott and Kourtney have proven to be awesome at co-parenting, and always appear to put their children first while keeping them out of any drama.
The 40-year-old stunning reality star has been posting pictures from her family vacation, and has definitely been enjoying her alone time before meeting up with the rest.
The eldest Kardashian has obviously had her hands full with three kids on this trip, but she brought some friends along to help out.
The group has spent time on yachts, shopping and more during their vacation, and they all seem to be having soaking up every bit of summer!