Best way to ask is to just ask. You don’t have to put your personal business on blast. Tell HR you’ll need some time off for surgery - you’re not obligated to tell them what type, although they may ask for a note. The note will have your doctor’s name on it. And there is this thing called the Internet. Anyone can find out anything. Even if HR requests a note, plastic surgeon does not have to specify procedure done, just that you’re under her/his care and will need a certain amount of time off or certain accommodations. Brazilian Butt Lift takes more than just the surgery to get a nice result. You’ll have to be off of your buttocks (no sitting or lying directly on buttocks) for SIX weeks to avoid misshaping the fat or killing the fat. You can use a special roll under your thighs to keep pressure off buttocks while sitting, but this roll is not inconspicuous. Are you prepared to do this mentally and physically? Will your work make accommodations?