This is a bit long but I don't want to drip feed.
We are friends with a couple who have a 4yo and a 2yo. DP and I went to school with the husband. Last time DP happened to see them without me and they raised concerns with him about my breast feeding our 3yo. DP didn't say exactly what they said but since they chose not to discuss it directly with me I did not bring it up with them. I am not militant or judgey about bf, it's just something I do with my DD and if people want to discuss it I am happy to otherwise I don't bring it up.
We saw them again last Sunday and I was sitting next to their 2yo for lunch. At some point she used her fork to prick my hand. I looked to her parents and they seemed to not have noticed because they were talking. Then she pricked my hand twice more and since no one reacted I said to her that we don't prick people with forks because it makes aou aou (with a nice calm voice and a smile). She then pricked her food and looked at me so I said well done that's what forks are for, then she pricked the plate and looked at me so I said that is fine, then a wallet that is OK, etc. I thought we were having fun and communicating. Then her dad said don't do that, so the next time she did it and looked at me I said daddy said not to do that and that was the end.
When they left DP asked me why I had upset our friends by disciplining their child and was it because I wanted to get back at them for the bf critiques. WTF? AIBU to think there was nothing to get upset about? And I certainly didn't do it in retaliation for a perceived slight! I only said something because no one else had noticed and I thought that pricking people with a fork was probably not a good habit to get into.