It is permissible for a woman to wear for her husband jeans and anything else she would like. In front of her maharim (sing: mahram, non-marriageable relatives), on the other hand, what is between the navel and the knees must not be tight because this is the woman `awrah (part of the body which must be covered) in front of her maharim according to the more lenient opinion that has been transmitted from the People of Knowledge. As for wearing jeans in front of non-mahram men, that is not permissible since they describe the contours of the `awrah.