Kylie Kelce is giving fans a peek at her growing baby bump — and having a little fun while doing so.The soon-to-be mother of four daughters shared a rare glimpse of her pregnancy in a humorous ad for Liquid Death, which aired on Tuesday, March 18.In the commercial, Kylie, 32, jokes about her hydration routine, holding up a can of the water and saying, "I've had so many of these today." She playfully adds, "I wish they would make a huge keg," before the jingle "Kegs for pregs, you're drinking for two" kicks in, followed by a montage of pregnant women dancing while sipping the water.Kylie's playful banter continues as she shows off a massive water keg, saying, "All for me and my unborn child! Drink up!" The commercial ends with her getting pulled over by a police officer, where she humorously states, "Why yes officer, I have been drinking... for two."This commercial comes just before Kylie and her husband, Jason Kelce, prepare to welcome their fourth child. The couple, who already share three girls — Wyatt, 5, Elliotte, 3, and Bennett, 2 — revealed in November that they are expecting another girl, though they've kept the name a secret.While the couple's due date has remained a secret, Kylie teased in an episode of her Not Gonna Lie podcast that she's "about to have three birthdays really close together." Bennett just turned 2 on February 23, while Elliotte just celebrated her 4th birthday on Tuesday, March 4, meaning that the baby will most likely be due later this month or next.When it comes to her kids' special days, however, there is one parenting trend Kylie will never participate in. "I am vehemently against the idea of other kids getting birthday presents on a child's birthday," the former soccer player also revealed on her podcast. "When your siblings get presents for your birthday, it reduces your birthday," she continued, adding that it takes away from the celebration's significance.