The Mood for Flashing - Propositioned, #4

Young wife Libby has been given permission by her husband to wear her skirts shorter and go braless if she wants: My wife remained standing close to her ex and he leant toward her again and touched her bare skin with the back of his fingers. Libby resumed stroking her daughter's hair and kissing her head while the child's father craned his neck for a more deliberate look down her dress. I swallowed hard and caught Libby's glance once, then again after another minute.
Her ex stepped inside for a second, returning without their child. There was a definite bulge in the front of his jeans, which he adjusted as he leant against the doorframe close to Libby again. Libby ran fingers down her neckline. Her dress was hanging down one arm, that slender shoulder bare. There was one button undone and she fiddled with the next one while chatting and giggling with her ex-lover.
She lifted both arms and raked back her hair. The second button on her dress had popped undone and the garment gaped even more. Her ex tilted in for a look and she pushed his head but was still giggling and blushing sweetly. She lowered her arms and put her hands behind her back while resting against the porch rail and thrusting her chest forward. Her ex looked over and met my gaze. I could feel my face was hot and knew I was flushed with the nervous excitement I was experiencing.
Libby turned her head to look back at me too and just glared defiantly.