All characters are 18 or over, naturally.
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His daughter Emily had turned 18 a few weeks ago. As it was a hot day, she had invited a couple of friends over for a swim in their pool.
The three girls quickly shucked their clothes and jumped into the pool in their bikinis.
Sipping his beer, Ryan watched surreptitiously through the living room window, appreciating their curves.
He tried not to look at Emily for too long, she was his daughter after all, and best not to go down that path, he thought. But looking at the other two felt less wrong.
Jessica was tall, with that lovely figure that only teenagers can have, before they eat too much, or get obsessed about their weight and eat too little. As she turned sideways, ready to dive into the pool, he admired the way her tits fell away from her body. Just perfect. And that swimsuit just gave them a little lift. He sighed, feeling his cock stirring.
Sarah, on the other hand, was shorter, and cuter. With a round face, striking features, and dark hair, she was easy to watch. Hard to turn away from. She exuded a sexy confidence, as if she understood and liked her own body.
The girls were diving in, hopping out, splashing and giggling. They had, in fact, noticed Emily's dad watching them through the window, but they didn't mind. Putting on a show for an appreciative audience was always fun. Plus they had hatched a little plan of their own.
Trying not to make it too obvious they put on a show for him. They made sure they stood sideways on to where he was standing, so he didn't feel self-conscious about watching them. They lingered at the side of the pool before jumping back in. They threw their arms back, supposedly straightening their wet hair, the action thrusting their already generous breasts out in profile for him.
After a giggled consultation in the pool they decided to try to ramp it up a bit. Knowing men usually don't mind watching a bit of lesbian activity they flirted with each other a bit, touching each other on the bum, and kissing briefly.
Emily didn't mind teasing her Dad like that. She knew he didn't get much action from her mother these days, and felt a bit sorry for him. Of course, she couldn't help him out personally (well, she hadn't so far), but she didn't mind titillating him, especially with her friends around, so it wouldn't feel so wrong for the poor guy.
Ryan watched for a bit longer and then decided he better get on with the household chores. He unpacked the dishwasher and tidied up the kitchen.
Meanwhile, after another giggled discussion, the girls decided to swim topless, to see if that would provoke him to come back and watch them a bit more. The discarded their bikini tops by the side of the pool, and jumped in, letting the pool water provide some level of modesty.
Ryan finished doing the dishwasher, and strolled back to his vantage point. The girls were just splashing around in the water now, not getting out, but there was something different about them, he couldn't quite figure out what it was.
A couple of minutes later he spotted it. Bare tits! His eyes almost boggled out of his head as he stared at them. His mouth dropped. His cock, which had previously settled down under the tedium of dishwasher-unstacking, re-asserted itself rather rapidly.
His hand dropped down to his pants and gently massaged his hard-on. Things were getting uncomfortable. Better walk away while he could. Suddenly the girls (who had spotted him out of the corner of their eyes) got out of the pool, and headed straight towards him, towards where they had left their towels.
He shrunk back into the room, hoping they wouldn't notice him perving on them. They picked up their towels and rubbed them all over their bodies, breasts shaking vigorously as they did so. There was a crash as Ryan backed straight into a lampshade, knocking it over. They giggled some more. Pretty successful.
Feeling a bit sorry for him now, they put on their bikini tops and came inside for a drink. 'See us swimming, Dad?' Emily asked.
'Uh, sure, just checking you were OK,' he replied with a guilty look. The smiled at each other.
Jessica thought she would have a bit of fun. Emily's dad was an OK guy, and she thought it would be nice to give him a bit of a treat.