Is completing the marriage to a girl whose family has agreed to her, without the parents' consent, considered disobedience to them, knowing that the son does not wish to disobey them or lose the girl?

Obedience to parents in what is good is obligatory. It is obligatory to refrain from marrying a woman whom the parents do not desire, because obedience to them takes precedence over marrying a specific woman. Marrying despite their objection is a sin from which one must repent. If the woman is not religious or of good character, then it is advisable to divorce her to please the parents, as Abdullah ibn Omar did. However, if she is religious, there is no impediment to keeping her while striving to please the parents and involving righteous people for mediation.