Stepmother gives my girlfriend a lesson in cunilingus and fucking for cheating

I had a friend who was always trying to get into my girlfriend's pants. I didn't like that, so I told my girlfriend to teach him a lesson. She agreed and went over to his place. When he saw her, he got excited and started to kiss her. My girlfriend let him do whatever he wanted. She even gave him a lesson in cunilingus and fucking. When he was done, she told him that he was a good learner. He was happy with the way things turned out and thanked her for it. Later, when my girlfriend came back home, I asked her how it went. She told me all about what happened and that she had a good time. I was happy to hear that. I knew that my girlfriend was bisexual, but I didn't mind. I still loved her and I was glad that she had a good time.