Golden Barbie has found a Ken!! 2020 S.I. Swimsuit cover model Jasmine Sanders is dating celebrity trainer Anthony Rhoades ... and it's so real, he got her name tatted on him!! Sources close to the couple tell TMZ Sports ... the two initially met through mutual friends in Miami ... and recently decided to take things to the next level. We're told Sanders and Rhoades have been "officially" together since early 2020. Rhoades -- who trains huge names like Rick Ross, Evander Holyfield and J. Balvin -- threw his girl a surprise private dinner at Kiki on the River in Miami on Tuesday ... complete with a MASSIVE cake and cut-out of her S.I. cover!! The couple was joined by friends David and Isabella Grutman ... as well as Aris Nanos, one of the restaurant's owners. As for the fresh ink, Anthony decided to commemorate his girl's big night by getting "Jasmine" tattooed on the side of his hand!! As we previously reported, Sanders actually has TWO covers this year -- one by herself and another including fellow S.I. vets Olivia Culpo and Kate Bock ... so yeah, it's a big deal. Rhoades congratulated Sanders on the accomplishment ... saying, "You set an amazing example for young women all over the world." "I’m beyond proud of you babe. I know how much this means to you and what it represents on a deeper level. Keep being the brightest star in the sky... this world needs guidance."