"Sister Wives" star Kody Brown knows there's only one way to please all 4of his wives on Mother's Day ... and it involves an ALL-YOU-CAN-EAT BUFFET IN VEGAS!!
TMZ spoke with the TLC reality star -- who tells us he's taking Meri, Christine, Janelle, and Robyn to the Red Rock Casino in Las Vegas for their famous Mother's Day Brunch buffet.
Kody says he isn't really a "breakfast guy" -- but his wives are huge fans of the Rock's quiche, eggs, and waffles ... and at $23.99 a pop, it fits in the budget.
Meanwhile, the Duggar family from "19 Kids & Counting" are also having a cost-friendly Mom's Day ... hitting church in the morning ... followed by a family luncheon honoring the women.
In other Mother's Day news -- TMZ also spoke with "Cake Boss" Buddy Valastro ... who told us he's finally gonna take the day off this year and spend it with his wife Lisa ... who gave birth to their 4th kid this year.