Can I ask to break in line?
Why are you going to ask to break in line?
The line is getting so long. It's so frustrating
It is good to ask others if it is okay to break in line.  It is bad to skip a line.
I'll be brief about it.
Being brief doesn't matter, just ask for permission. You'll upset a lot of people by just skipping in line, and could even get into an argument that you may want to avoid.