A garment with a flexible fabric shell has a pocket or vent opening with a resealable closure such as a zipper, snaps, or hook and loop fasteners, which is operable between a closed position, in which the opening in the shell is closed, and an open position, in which the opening in the shell is revealed. A resilient spring member of springy plastic, composite, metal or other material is mounted to the fabric around the opening, and has two arms which have portions which are displaced vertically from one another when the closure is open, but which are resiliently compressed into a common plane when the closure is sealed. Each time the closure is opened, the spring member urges portions of the shell on either side of the flap apart, to thereby enlarge the area of the opening and permit access or air flow therethrough.