Fans of Kourtney Kardashian and Travis Barker have many questions after spotting what appears to be a baby bottle filled with milk in the corner of Travis's Instagram Story post late Sunday.
"Hi @travisbarker you can't just post a pic of a baby bottle and be like 'Imma just leave this here,'" a fan account captioned a screenshot of the mysterious bottle.
Reality TV star Kourtney, 42, and drummer Travis, 46, announced their engagement in October after dating for about a year. Kourtney, who has 3 children with ex Scott Disick, is not expecting.
Kourtney and Travis don't have children young enough to drink out of bottles.
Some IG users assumed that Kourtney's little sister, Kylie, had her baby.
But if Kylie had her baby it would be a newborn -- too small for a 16 oz baby bottle. It's also doubtful that the baby bottle belongs to Kylie's 3-year-old daughter, Stormi.
Internet sleuths who follow the growing adult baby niche online say the bottle in the IG Story looks like an adult baby bottle.
Adult baby bottles (pictured) are sold on Amazon, Etsy, and eBay under unassuming names as novelty items or as gag gifts.
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The bottles are also popular with online communities dedicated to "adult babies", "littles" and "regressors" in search of other adult babies, mommies or caregivers to act out their fantasies.
One woman, who calls herself "Motherly," provides instructions on how to make adult baby bottles out of a 16 oz glass jar and parts sold online.
Walmart sells large silicone Y-cut nipples (best flow for an adult) made by "Little Giant Kidz" for $15.40.