The Amazon founder, 57, took to Instagram Saturday to share several snaps from the St. Bart bash, which was attended by Sanchez's ex-fiance Tony Gonzalez and his wife October.
Gonzalez - a former NFL star who dated Sanchez until 2015 - was accompanied on the $38,000-a-week chartered yacht by the adult son they share, Nikko. Also aboard the 88-foot boat was Bezos' young brother Mark, and others.
Although they in 2005, Sanchez and Gonzalez appear to be on good terms, and have been spotted together with Bezos on previous occasions.