Do you agree that children need more discipline!?

I was walking back from the shop with my boyfriend yesterday, and there was a group of children aged about 7-8. They weren't playing though, just sat on the wall talking. Me and my boyfriend were holding hands and the children said to us.... ewww get a room! and then a young girl said.. look at them, she's a right s.l.a.g! she spelled that word out, obviously too young to be saying things like that. I was really annoyed by their comments, i cannot understand how children of that age understand what those things mean. also, it wasn't like we were getting it on right their in the street! we were walking and holding hands. at that age i was more interested in what i was going to dress my dolls in, not what i was going to say to strangers ping by. do other people agree that children need more discipline and parental guidance?