The only thing tougher than defeating Thanos may be sitting through “Avengers: Endgame” without needing to use the bathroom.

Disney’s DIS, +1.95%[1] long-anticipated superhero blockbuster, which officially opened Friday (after breaking records a day earlier[2]), is the Marvel Cinematic Universe’s longest movie yet, clocking in at a walloping three hours and one minute (not counting the coming attractions shown beforehand). The sequel to last year’s “Avengers: Infinity War” juggernaut, which ended on a cliffhanger that saw half of the universe's population wiped out with a snap of galactic warlord Thanos’s fingers, is also the culmination of the 22 previous Marvel movies (including the “Iron Man,” “Captain America” and “Thor” series, as well as “Black Panther” and “Captain Marvel”) spanning the past decade.

See: Good luck getting ‘Avengers: Endgame’ tickets[3]

A lot is riding on this movie, which has enjoyed record presales[4] and is expected to earn between $250 million and $268 million in North America alone[5], if not more, over its opening weekend. And fans don’t want to miss a minute — especially those who might shell out $500 on eBay for tix to sold-out showings — but 181 minutes can be a long time without a run to the rest room.

Read: Some tickets to ‘Avengers: Endgame’ are selling for $500 online[6]

So viewers are fretting about which moments might be “safe” for a quick dash to the john under the hashtag #whenshouldipee, and sharing strategies like dehydrating themselves or joking about wearing diapers to prevent missing a climactic scene because nature has called.

“You need to plan potty breaks in a 3 hour #AvengersEndgame movie. Eat salty popcorn and skip the drinks just in case,” tweeted one.

And a few lucky early birds who were able to see screenings ahead of the Friday opening have also poured on the advice — or patted themselves on the backs for watching the entire movie in one sitting.

Currently mildly dehydrated because I'm heading into an #AvengersEndgame[7] screening in a bit and don't want to have take a pee break.

— Tom & Lorenzo (@tomandlorenzo) April 23, 2019[8]

NO SPOILERS!! I made it through #AvengersEndgame[9] without needing a bathroom break OR peeing myself.

— Jon Risinger (@JonRisinger) April 23, 2019[10]

For anyone who wants to know the best time. THERE IS NO TIME TO PEE. HOLD IT IN. #AvengersEndgame[11]

— Cheaper by the Rhojan 2 (@_rhojan) April 24, 2019[12]

In fact, a few movie reviews[13] have even included recommendations on when...

Read more from our friends at MarketWatch