Celebrity Parents Ashlee Simpson Ross Calls Son Bronx the 'Coolest Teenager' as She Wishes Him a Happy 13th Birthday "This is 13," the singer wrote alongside a black and white photograph of the mother-son duo By Nicholas Rice Nicholas Rice Nicholas Rice is a Senior Editor for PEOPLE Magazine. He began working with the brand as an Editorial Intern in early 2020, before later transitioning to a freelance role, and then staff positions soon after. Nicholas writes and edits anywhere between 7 to 9 stories per day on average for PEOPLE, spanning across each vertical the brand covers. People Editorial Guidelines Published on November 22, 2021 04:02PM EST Photo: Steve Granitz/WireImage Ashlee Simpson Ross officially has a teenager on her hands! Over the weekend, the 37-year-old singer paid tribute to her son Bronx — whom she shares with ex-husband Pete Wentz — as he celebrated his 13th birthday. Sharing a black and white photograph of herself beside the teen, Simpson Ross wrote, "This is 13. Happy birthday Bronx! You are the coolest teenager. I LOVE YOU. I LOVE YOU. I LOVE YOU." In the comments section, some of Simpson Ross' famous friends left sweet messages for the mother-son duo. "OMG 13," Rachel Zoe wrote as makeup artist Mary Phillips said, "Stop!!! Omg it feels like yesterday he was in your belly." Along with Bronx, Simpson Ross is also mom to the two children she shares with husband Evan Ross: son Ziggy Blu, 15 months, and daughter Jagger Snow, 6. (Wentz, 42, is also dad to 7-year-old son Saint Lazslo and 3-year-old daughter Marvel Jane with his wife Meagan Camper.) Never miss a story — sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from juicy celebrity news to compelling human interest stories. Ashlee Simpson Ross Shares Rare Family Photo Featuring Husband Evan Ross and Her Three Children On his respective Instagram account, Ross, 33, also sent some birthday love his stepson's way. "BRONX HAPPY BIRTHDAY KING! LOVE U," the actor wrote alongside a selection of pictures of the two at what appears to be an amusement park. Simpson Ross and Ross tied the knot at the Connecticut home of the groom's mother, Diana Ross, in August 2014. Back in March, Ross opened up about spending quality time with his wife and family during an appearance on the PEOPLE Every Day podcast. There, he shared that he's thankful for the moments they've had together during the ongoing COVID-19 pandemic. "You take it [one] day at a time," he said during the appearance. "All in all, you've got to remind yourself of how lucky we are in the sense that we get to have these moments that we may have not had the same way, if we [would have had] to work."