My spouse has an embarrassing weakness. Can I tell a close friend about it?

Spreading your spouse's faults to others hurts their dignity and rarely solves anything. Venting that feels like relief often comes back as a story that spreads and causes shame. If you need to talk, choose someone trustworthy and knowledgeable, such as a counsellor or someone who can advise without spreading it, rather than venting just to gossip. Better still, take the issue to your spouse first, in a kind way. Guarding your spouse's faults is part of the covering of faults that Allah asks of Muslims towards one another. See counselling.