Aunt/nephew (m4f)

It's a hot summer day and you have a pool. Getting to relax, tan, and swim was amazing. But the downside was your nephew was constantly coming over. You understand since it's hot and he's just trying to cool off. But some reason, you feel like you have eyes on you when you're tanning or bending over to pick something up. Not like he is staring at your or your ass right?

Well today was another hot day and you decided to wear your new bikini. Showing off your body but it barely covers your chest and leaves little to no imagination of your ass. Like normal, you weren't expecting anyone but you hear, "Hey auntie...wow that's um...wow!"

You turn around and see your nephew and you could tell he was staring at your ass. His eyes gave it away and so did a growing problem in his shorts. So what do you do? Tease him, point it out, or see where this goes?