Movies are expensive. The last movie I went to was $12 a ticket. Under no circumstance could I convince myself a movie was bad enough to leave that $12 on the table and walk out. I almost did with Paul Blart: Mall Cop. But for some people, they decided to take the hit and walk out on these movies.

Titanic

I had to leave during Titanic. My friend that I was there with began hysterically crying once the ship began sinking and declared she couldn't watch the rest. I was kinda annoyed, since it's not like it was a surprise that the ship was going to sink. I only left with her because she was simply inconsolable and making a scene at that point.

South Park: Bigger, Longer and Uncut

Friends dad took us to see South Park: Bigger, Longer, and Uncut. He decided it was too vulgar for us about 20 minutes in (we were 12). He decided to take us to Hooters instead. 9/10 would do again.

Austin Powers: The Spy Who Shagged Me

It wasn't my choice, but when I was a kid I went to watch Austin Powers: The Spy Who Shagged Me with my mom and my friend. My mom was already pretty disgusted with the movie during the first 20 minutes. The tipping point for her was when Fat Bastard was laying in bed with Heather Graham and she puts that little tracker thing up his ass. My mom got furious and said we weren't watching anymore of it and we walked into Star Wars Episode 1 instead. Go figure.

Grandma's Boy

My dad, my 11 year old sister, and my 21 year old self thought it would be nice to take my grandma out to dinner and a movie for her birthday. There was a lighthearted comedy in theaters at the time about a grandson who fell on hard times and had to move in with his grandmother, and hijinks ensure.
We took my super conservative 87 year old Christian grandmother to see Grandma's Boy. I think we made it to the point where Alex masturbates in the bathroom before grandma loudly proclaimed everyone in the theater is going to hell and we had to leave.

Harry Potter and the Half-Blood Prince

When the 6th Harry Potter movie came out we had to pretty much drag my friend to see it. He's a military guy who hates fantasy movies. I was shocked he even agreed to go, albeit reluctantly. One of the first lines of the movie was "Ok, Harry. Wand at the ready." And he loudly scoffed. About 10 minutes into the movie, while Harry and Dumbledore were attempting to recruit Slughorn a lone chair sat in the room of an empty house. I whispered to my friend, "He's the chair." His response was, "If he's the chair....I'm leaving." Sure enough, Dumbledore prodded the chair with his wand. Slughorn's head popped up, exclaiming, "Merlin's beard!" My friend kept his word.