For them it used to be nothing special any more and they loved simply to have a day off also off of family duties.

Eat a lot.

Sometimes they'll have a little party at home with friends and neighbors, or they'll go out to dinner. Usually they keep it low key unless it's a "milestone" birthday. I'm kind of the same way. XD

They don’t do much!

Celebrate w kids and grandkids. Doesn’t matter how or where.

go hang out with friends

roast me I guess, I wouldn't know

Very timely question since tmrw is my mom's bday. I take my parents out to eat

Not much I usually just go out to dinner with them and have a few drinks