BS”D
Also, the problem here is that we (and I am the most guilty because I discussed CY in the wrong thread) are confusing halacha with minhag.
Not wearing jeans is a communal minhag but if they are clean and respectable the issur is only a communal one with no real halachic validity. (Ditto for denim skirts; I understand that some communities frown upon them as do some families, but in most places if they are clean and the right length you’re usually well within the rules).
On the other hand, going to shul in dirty jeans or hip hop styles is a bizayoin. If you are a known entity in your shul and you show up like that, unless it is obvious you’re in the middle of cleaning your home or car and you wanted to run to minyan because you might be #10, expect stares and dirty looks because you’re not treating the shul with proper respect.