That's a hollywood invention.
I've never met any man stupid enough to ruin his pants with the butter from the popcorn, ruin the bucket of popcorn itself, and burn his own penis and essentially waste money on a movie ticket and popcorn.
It's multiple Ls. You spend money on a bucket of popcorn, have to somehow find a way to cut a hole in it without the popcorn all spilling out, undo your pants and put your thing in there without nobody seeing or hearing you do it and then if she reaches in for popcorn and feels that she may be disgusted, leave the theatre, and text all of her friends about what a fukking weird creep you are.
If you're actually getting p*ssy you don't need to do some weirdo sexual deviant shyt like that. If you're actually attractive and the woman is down, she'll stroke you in the theatre and enjoy it without you having to say or do much.