Not a teacher but I used to do a lot of school discos and my god those are interesting
I am very careful when I put a playlist together for a party whether it's for a kids party or anything else and although I don't tend to do mobile DJ work anymore, I do DJ at my pub as it's saved me a fortune and have, when requested, sorted out music for parties at the pub.
I was asked to DJ for a year 6 leavers party and was so careful, I had used a program to cut a section from a Little Mix song (school had asked the children to make a list of songs they loved and LM featured heavily).
Had a mum come over and complain because she thought I had played the Dua Lipa song New Rules. I hadn't, I played the very tame Kidz Bop one. She refused to believe me. Had to show the Headteacher my playlist which didn't contain the offending song.
At the same school, a teacher asked me to play Stormzy. He was confused when I said it wouldn't be appropriate as the lyrics in his choice are not suited for the age group.
Two parents dancing to a slower number, only for me to find out that they were both married to someone else when the wife smacked the other woman in the face.
Another one, I used to play a few old party/school disco classics as they went down well with the parents and teachers. Kids used to love watching their usually straight laced teacher doing Saturday Night or YMCA and they'd laugh and join in.
At one school, I received a lovely bunch of flowers and card from the school a few days after playing, with a note from the headteacher that a parent has complained about YMCA as it was a "gay song" and she didn't want her DS being fed "gay propaganda". The headteacher sent it with a comment on "thought you'd find this amusing" which I did.
Although I was once at disco for my DCs infants school, a CofE no less, where a DJ had clearly not checked his songs and the children were treated to a venue sweary rap song which he continued to play until a teacher pulled a plug from behind his set up. The complaints that time were plentiful.