I only want to sit on the aisle whether it is on an airplane, in a theater, or any other event, because I don't want to be the ONE putting my FRONT or REAR in the faces of others! (See the URBAN DICTIONARY item below). The Urban Dictionary writer seems to think BACK-FIRST is preferable, but I think both are equally distasteful. If I am forced to be anywhere in a place in other than a seat on the aisle I will STAND to avoid the back or front of others.
Ziggy, the husband of my husband's grand-niece Aron, prefers the front-side from women because he enjoys a little frottage! (CLICK HERE to see BLOG article "ZIGGY".)
When someone walks in front of you getting to their seats at a sports event and they choose to go facing you. If you are still sitting down then it will be their crotch to your face. This is considered poor practice and should be replaced by their backside in your face.
I was at the game last night and these guys walked past us to get to their seats and they went by crotch-first. It was so gross.