I have 4 DS aged from 11 to 17. The eldest in particular at times uses what I would consider to be sexist phrases to insult his brothers - this morning he was winding my 15 yo up and when the 15 yo complained he shouted " Mum, you need to get * some tampons!!" I was not impressed understatement and told him off in no uncertain terms but wonder if there a more constructive way that I could approach this with them rather than simply getting bloody angry with them!!
Their father (exH fortunately) and his father (exFIL) make this type of comment often which is where it comes from I guess. One of FILs favourite comments was "never trust something that bleeds for a week and doesn't die". My DP is not like this at all and is very angry with them too (he has 2 dd and gets exceedingly annoyed about sexism too).