Excellent!
I bet they have the audacity to complain about it as well. 'Discrimination', no doubt the cry as the they throw donut after donut down their throat, swigging from a '60 oz' dustbin of Coke. I'm not exactly an adonis, but can comfortably fit myself into one seat, and fasten the seatbelt without hassle. If you have decided to feed yourself on lard butties all your days and can't snuggle into a seat without your gargantuan bellying splling over onto my lap, then you deserve everything you get. Paying a double fare is little in comparison to throwing your life away.