I share things with both my parents and friends. It's important to share things with your parents as well because they've already experienced life. Parents can give you the most and better advice than anyone else . If you share with your friends there's always a chance they can use that information against you if you guys ever get into a fight.
If it is something outside of my marriage/relationship, yes.
If it is something pertaining to it, then no. A sympathetic ear is not an objective one and sometimes in their well-meaning attempt at helping, they could end up hurting you and that could take a minor issue and turn it into a rift between you and your partner/spouse.
So it is for that reason, that any disagreement or issue I have with my husband I talk to him about it and we resolve it ourselves.