I know it's CUSTOMARY
for the birthday boy to receive presents,
The Big Bang Theory Season 9, Episode 17
...in order to indulge in your CUSTOMARY
preemptive pre-show urination.
The Big Bang Theory Season 3, Episode 5
It was CUSTOMARY for me
to extend him an invitation.
Game of Thrones Season 2, Episode 5
It's CUSTOMARY, when
using the restroom
The Big Bang Theory Season 5, Episode 13
It is CUSTOMARY to kneel
when surrendering to a king.
Game of Thrones Season 4, Episode 10