Sal Stewart Jr. debuted in the MLB for the Cincinnati Reds on September 1, providing an energetic spark to their push for a playoff spot. Though the Reds crashed out in the Wild Card series, Stewart created history, becoming the youngest player in franchise history to start a postseason game.Earlier in the regular season, Stewart became the youngest Reds slugger to debut at first base in 117 Years. One person who has been thick and through with Stewart is his girlfriend, Natalie Espinosa. Along with Stewart's parents, Natalie was at the Great American Ball Park to watch his debut.On Sunday, Stewart shared a snap of Natalie on his Instagram story. Donning a zebra-printed bikini, she sat on a yacht. She held a cigar in his right hand and a straw hat rested on her lap. Natalie also wore sports sunglasses.The image was taken from the Billy Point, a location in Biscayne Bay, Florida, situated south of Elliott Key. Known for its beautiful turquoise water, the location is a destination for boaters.Screenshot of Sal Stewart's Instagram story [Image Source: Instagram/salstewartjr]Sal Stewart Jr. gushes over girlfriend NatalieThe Cincinnati Reds called Stewart to the majors from Triple-A Louisville on September 1. After recording his first MLB hit on his debut against the Toronto Blue Jays, Stewart hit his first MLB home run on September 6 against the New York Mets.The year 2025 was certainly a memorable one for Stewart Jr., not just professionally but also personally. Long before his MLB debut, he shared a multi-photo Instagram post in June, giving fans highlighting his relationship with his girlfriend, Natalie.In the cover image of the carousel, the couple posed together outdoors on what appears to be a wooden porch. Stewar wore a dark shirt, while his girlfriend donned a green puffy jacket and held a rifle."The best year❤️ I love you [Natalie Espinosa]," Stewart captioned the post. View this post on Instagram Instagram PostThe next photo in the carousel was a selfie taken by Sal Stewart, with Natalie resting her head gently on his shoulder. The third image showed Stewart Jr. striking a hilarious pose while holding Natalie. This was followed by a snapshot from what appeared to be a dinner date,Then came a short video of Natalie showing off her golf swing. The second-to-last image seemed to have been taken shortly after the 2025 New Year, showing the couple cuddled up on a sofa. The final photo was a beautiful solo shot of Natalie.