I can’t believe no one even bothered to explain the issue of Jeans. While I am not neccessarily sure myself where I stand on the issue, this is how it goes: 1rst of all Jeans are sort of rough and tumble, casual…the idea is that Yeshiva Bochurim should look respectable, upperclass, neat… while there is nothing wrong with the casual look, and its certainly not “evil” most yeshivas and yeshivish people feel its not appropriate for everyday and doesn’t keep within the respectable neat image they want to portray. Personally I feel that the casual look should be reserved for the summer, and camp or hiking.
2nd of all, there is a certain look/attire that yeshiva boys have that makes them fit in with the group and look like a yeshiva boy. This includes a white shirt black pants, maybe a black hat… it really depends on the crowd and yeshiva. So if your son is coming from a crowd where its not the standard mode of dress to wear jeans, it seems quite obvious that he’s trying to stand out and look a little “cooler”. If your ok with that, no problem but be aware that it probably won’t end there. If he is looking for attention from the cooler crowd he will most likely start doing other things you may not approve of.