So after SIL caught me red handed with her panties in the restroom, she said she would keep quiet about it as long as I jerked in front of her with her panties. I felt blackmailed or like it was a set up to see how far I’d take it. I ended up texting her to see when she wanted me to go over. I arrived at her house later that day and she greeted me at the door smirking and laughing. I was embarrassed all over again. She takes me to her bedroom and tells me she has a pair of panties that she fingered herself in and got her juices all over. I asked her exactly what she wanted me do and to ensure nobody was ever going to find out about this. She nodded and told me she wanted to see me jerk my cock while sniffing her panties, putting them in my mouth, and stroking with them wrapped around my cock. Now I’ve never done this type of fetish with my own wife or any other girl. This was definitely a first. I asked her if she was going to be naked or I could see her tits while I do this, and she said no! She gives me the panties and tells me to start. There I go, cock is out in front of SIL and I start sniffing and stroking. It’s taking me longer than usual to get fully erect cause I’m nervous and SIL is sitting there starring. They smell amazing. Great pussy scent. I go to place them in my mouth when I notice her start rubbing her pussy. I stop and ask her if I can please see her pussy or to join me. She gives in and removes her shorts. SIL has a very nicely trimmed bush, as she starts rubbing herself. I’m erect at this point and wrap her panties around my cock as I start getting closer to her. She’s breathing heavy now and making moaning sounds. Then I ask her if I can eat her out and make her cum. She says that wasn’t part of the deal. I said I know but we’re here now and nobody would have to know. Surely if I convinced her mom, i should be able to with her. Super hesitant as I was stroking my cock near her now, she finally agreed. I spread her legs open and started kissing her inner thighs before tasting her and licking her. Felt good as she was moaning louder now. I slowly put two fingers inside her and she tried to move my fingers out of her but she couldn’t resist. I was now fingering her and eating her pussy. She cummed good as her legs started shaking. I asked if I could jerk and cum on her bush and she said yes. As I was cumming on her I wanted so bad to stick my cock in her. She cleaned herself off and re assured me what just happened would stay between us. She let keep her pair of panties.