We both are naked, I cleared some doubts in maths for about 4hrs that day, but I can’t take my eye from her.That night our parents were earlier. We ...ad dinner & we both were in bed.Next day was also same.The 3rd day she was studying social & I was surfing the internet in same room. All of sudden I had a plan to make her watch a sex video.So I opened porn site, open on a video & left for bathroom leaving the video to buffer.As I left she started to watch the desktop.When I returned she asked me. When we moved back to the couch, she again sat next to me. I stood her up and examined the G-string more closely, pulling it away from her at the side to reveal her freshly shaven pussy. It was beautiful, a perfect cleft with a small pussy. I asked her how it felt to wear it. She answered, "it's comfortable but scandalous. The other one is less so..."The other one?I asked her to wear it. She went back into the bedroom and changed into a non-lacy G string. I wanted so much to follow her into her. They hadn't been getting along lately and usually it was him that slept on the couch. "I broke down on the side of the road last night and my cell was dead", she answered. "I was stranded there for a long time until a very nice couple stopped and gave me a ride home". He looked at her for a few seconds then spoke in a low but stern voice. "Really"? "I guess it was well after some biker used our driveway to turn around", he added. He kept staring into her eyes and she was doing her best to not. I have some things to do while you're doing that, then I'll shower while you're both dressing."With that I swatted Brenda on her ass a couple of times before she finally roused herself. It took a couple of more swats to get her motivated enough to move. You could see the pattern of my hand on her reddened ass and I thought for a second of really spanking her.While mother and daughter were in the shower I made a few calls and set up a couple of appointments for later in the day.When we met again.