Alessandra Ambrosio showed off her fit figure in a tiny, triangle bikini as she soaked in the sun in Miami on Saturday. The 45-year-old supermodel wore a striped, black and white bikini as well as an eye-catching diamond on her ring finger amid rumors she has been secretly engaged for months.She further accessorized with other dainty gold jewelry, and for her beach day, she sported a pair of aviator sunglasses with a white frame.The former Victoria's Secret Angel was later seen with her hair wet and her body dripping after emerging from the clear, blue waters after taking a dip in the ocean. Her outing comes shortly after she fueled rumors she is engaged, or even married, to her longtime boyfriend Buck Palmer.Just one day earlier, she was seen modeling for a photoshoot on another Miami beach outing and flashing the dazzling piece of jewelry on her ring finger. Alessandra Ambrosio flaunted her toned, supermodel physique in a tiny, triangle bikini while enjoying relaxing time off on a beach in Miami over the weekendAmbrosio has been dating the 44-year-old jewelry designer since late 2024.Since the spring, Ambrosio and her beau have been at the center of engagement rumors as the supermodel was seen with a mesmerizing piece of jewelry on her ring finger as early as February. The couple fueled rumors they secretly tied the knot after they were spotted with matching gold bands on their ring fingers in April.'If Alessandra is engaged she has not told her friends yet, but everyone feels like she and Buck are headed that way because they are very serious and in love, so this may be a big hint from her that they are headed toward matrimony,' a source exclusively told The Daily Mail in April.'It is likely that he designed that ring she is wearing on her wedding finger because that's his job,' the insider noted. 'He designs jewelry.'Ambrosio and Palmer were first romantically linked at a party during Miami's Art Basel two years ago.Insiders confirmed at the time that the smitten fashion model hoped to be with her new partner 'for her entire life' due to their deep connection.'Alessandra knows who her New Year's Eve kiss is going to be, and she hopes to have the same man to kiss for every New Year's Eve for her entire life,' a source exclusively dished to the Daily Mail at the time. The supermodel was seen taking a dip in her skimpy, striped bikini as well as with a massive rock on her ring finger amid rumors she is secretly engaged or married Over the past few months, Ambrosio and her jewelry designer beau, Buck Palmer, have been fueling engagement rumors as they were spotted with jewels on their ring fingers on multiple occasions Since the spring, Ambrosio and her beau have been at the center of engagement rumors as the supermodel was seen with a mesmerizing piece of jewelry on her ring finger as early as February; pictured in May'She has been through the wringer in relationships but really truly believes in love and feels like she finally found it.'Opening up about struggles she faced in her past relationships, the insider continued: 'She has been a serial monogamist in a sense and loves being in relationships but has been with men that are resentful of her fame and her money.''She's been told so many times that she didn't have to work and had everything handed to her and that isn't true. Buck doesn't do this.' The source added: 'He is incredibly successful in his own right as a jewelry designer and of course he designs special pieces just for her.' In April, another source noted that the couple's relationship was going swimmingly.'She has never been happier because he has a great sense of adventure and likes to try new things, he is perfect for her,' an insider said. Ambrosio has been dating the 44-year-old jewelry designer since late 2024. Ambrosio and Palmer were romantically linked at a party during Miami's Art Basel Ambrosio was previously engaged to American businessman Jamie Mazur from 2008 to 2018; pictured in October 2015 The former couple share daughter Anja, 17, and 14-year-old son Noah; pictured in May Ambrosio is an iconic Victoria's Secret Angel who recently walked the runway for the lingerie brand in 2025'She is not opposed to getting married, she is being open with her heart, so who knows they may walk down the aisle,' the source continued.Previously, Buck was married to Australian model Ashley Hart for two years before they called it quits in 2017. Ambrosio was previously engaged to American businessman Jamie Mazur from 2008 to 2018. The former couple share daughter Anja, 17, and son Noah, 14. Between her relationships with ex-fiancé Mazur and current boyfriend Palmer, Ambrosio was romantically linked to Nicolo Oddi from 2018 to 2020 and model Richard Lee from 2021 to 2023.