I was on the tube earlier and a family with 2 children (aged around 7-9) were sitting next to me.
Mum got out a bag of sandwiches (ham and cheese) and gave one to the younger child, who was messing around and being silly and dropped the sandwich on the floor.
Oh well, no harm done, mum has a whole bag of sandwiches to replace it with! Or so I thought....
Mum picked up the sandwich, put the 2 halves back together and handed it back to the child who started eating it 
I know I'm strict about hygiene, but surely this is disgusting...or totally normal? Who knows what's been on that tube floor... 
FYI, the sandwich landed filling side down and was there for about 7 seconds, if that helps you decide.