blab

they blab on about responsibility.

Who will open himself to a blab?

She will be sure to blab and it will be all over the town in no time.

can't be trusted with a secret—he always blabs;

He blab bed my confidences to every one.

He lets everyone else talk and blab and yabber away, all these guys trying to impress the women, and he just calmly listens from the edge of the group.

Marty: No sirree, I'm telling you! It is bad luck! If you want some bad luck, I'll blab it out, but if you wanna be safe …