Gossiping about your team to other people is a leak. Eventually it reaches the people you talked about.

Information moves. Anything you say about a teammate to somebody outside the group tends to find its way back, usually in a worse version than you said it. The cost is not only that one awkward moment. Everyone who hears you talk that way quietly files away that you might do it to them, and trust is built mostly out of what people believe you say when they are absent.

Notice the pull to vent about someone this week and take it to that person instead, or to nobody. If you need to think it through, pick one person who can actually help. Keep names out of the rest.