On a flight from LGA to DFW. I was in the aisle seat. Went to the bathroom, when I came back a woman was in the middle seat.
There was a guy in the aisle in front of me. He turned around and asked "can we switch seats so I can sit next to my fiance"
I said "sure"
He said "i have the middle seat"
I said "middle seat on a 3plus hour flight? Sorry, maybe the other folks will switch"

"plus you are getting married, u will be together for the rest of ur lives, 4 hours apart is nothing, and might even be a good break from each other"

They didn't find my comment amusing, oh well