It's CUSTOMARY, when
using the restroom
The Big Bang Theory Season 5, Episode 13
...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
I know it's CUSTOMARY
for the birthday boy to receive presents,
The Big Bang Theory Season 9, Episode 17
it has been CUSTOMARY for our ruler
to make the rounds of the lower pits
Game of Thrones Season 5, Episode 7