On the tube. A toddler approx 18 months at a guess is in a pushchair with his mum stood behind him. The toddler is sucking and chewing on a plastic bottle lid. I immediately thought that he could choke on it. The mum doesn't seem to notice/ care. I wondered if she had realised what he was doing. Toddler then drops lid on the tube floor and it bounces over to my feet. I thought "Well it's a plastic bottle lid and now it's been on the floor of a tube carriage where millions of people and some dogs walk everyday she won't want it now." Also as a toddler had been chewing on it I felt no inclination to pick it up or touch it. A woman next to me bent down and picked it up and handed it straight back to the mum who gave me a dirty look as I had not picked it up, then (there was not even so much as a wipe not that that would help) gave it back to the toddler to suck/ chew. This happened twice in three or four minutes whilst I was standing there. AIBU to think this is slack/ careless/ dangerous parenting? Surely not safe for a young child to suck a bottle lid especially when on and off the tube floor? AIBU not to have been retrieving the lid for the child?