First posting a video of Guobadia dancing poolside, Williams then showed off other fun moments from the outdoor celebration, including videos of partygoers on an inflatable water slide and clips of Guobadia opening up an extravagant gift from his love — a Franck Muller watch.
In another post, Williams plants a kiss on her beau as he holds onto a bouquet of gold-colored flowers. "Nothing but the best for you babe! ❤️," Williams captioned the post.
Closing out her documentation of Guobadia's special day, Williams also shared a video taken from inside what appeared to be a strip club. In the clip, dancers are seen in front of a giant screen featuring a picture of Guobadia with "Happy Birthday Simon" written across it.
Guobadia — who is the estranged husband of Williams' RHOA costar, Falynn Guobadia — announced that he and Williams were engaged on May 10, just a month after the couple started seeing one another.
"I asked her to marry me because we checked ALL of each other's boxes, and then some," he wrote on Instagram.
"Our relationship began a month ago—yes we are crazy in love," Williams wrote in an Instagram post that same night, alongside a selfie with her love. "I know it's fast but we are living life each day to its fullest."
"I choose happiness every morning and every night," the mom of one added. "Tuning out all negative energy and only focused on positive wishes. He makes me so happy and to me, that is what matters most."
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Guobadia's estranged wife, 31, announced her split from him after two years of marriage on April 22.
Addressing her new relationship, Williams wrote on her Instagram post, insisting that though the pair's divorce has not been finalized, the former couple have reached a settlement agreement.
"For all of you that need facts, I get the optics but Simon filed for divorce from a previous marriage in January. I had nothing to do with their divorce filing. That's between the two of them," Williams continued. "Falynn and I are not friends, and Simon's divorce has been settled. Our relationship is a positive, loving step forward in everybody's lives."
This will be the second marriage for Williams, who was previously married to NFL star Kordell Stewart, from 2011-13. She shares 2-year-old daughter Pilar Jhena McKinley with ex-fiancé Dennis McKinley.
RELATED VIDEO: Porsha Williams Says She's Planning 3 Weddings with Fiancé Simon Guobadia — 'And a Funeral for the Haters'
Elsewhere on Instagram, Williams — who recently revealed that she got Guobadia's middle name tattooed on her neck — also showed off that she bought Guobadia not one, but two custom birthday cakes to celebrate his birthday on Wednesday.
Williams shared a photo of Guobadia smiling next to the cakes — one of which was designed to look like a box of Cohiba cigars.
"Happy Birthday Fiancé! 🥰" Williams wrote on Instagram, later sharing on her Story a video of Simon's birthday dinner, which included lobster tails and a tower of chilled shrimp.
In a post of his own, Guobadia said he was feeling "blessed and thankful to be celebrating another birthday."
"I don't take my life and blessings for granted," he wrote alongside a photo of his family sharing an extravagant birthday brunch. "Spending with my kids makes it even more meaningful🙏🏾."