[F] I (42F) let my son’s friend (M19) fondle my legs

Back in the 2020 lockdown, I really got into yoga and started free classes for some of my friends. Over time, they got more popular and now I am somewhat of a yoga instructor. It’s still a small thing, except that now the circle has extended to friends of friends of friends, rather than only friends.
One of my son’s friends joined these classes last month. Right from the start, he was extremely flirtatious. I had some experience in dealing with guys like him, but his flirting was almost mathematical (I don’t have a good way to explain it). He would know when to stare, when I’d get annoyed, how much to push me, and when to back off. Over time, I got comfortable with his flirting, but I did not flirt back.
Today in the morning, he stayed back after the session and was asking me questions about handstand. I was in a cheerful mood and I was showing him the correct way to do it step by step. He could also do it, but his spine was all bent. He was balancing himself by moving his legs, rather than maintaining a stable balance without moving his legs. As I was helping him, he said “I wish I could do it half as effortlessly as you do it. I look like a flopping fish and you elegant like Ariel (from the little mermaid).” I blushed.
I said, “I’ll do it once again, slowly. Watch me closely.” I was wearing pink ombre yoga pants and a crop top. When I was in position, I said “You see how my legs aren’t strained? How they’re relaxed?” He brought his hand close to my calf muscles and looked at me, asking for permission. I said “Sure, go ahead, see how they’re relaxed.” He touched and gently pressed my calf muscles. I had to use all of skill to not twitch in response to his touch. He then kept sliding his hand towards my thighs and I pretended to be professional about it. His hands were on the back of my thighs and he was touching and gently pressing against them. I wanted to flirt back today. I had wanted to flirt back for quite a while, but never did. I wanted him to touch me more. I said “Relaxed all the way to the spine.” I wanted him to move his hand over my butt but I wasn’t sure if he would do it. He looked at me and I smiled a very neutral professional smile. He moved his hand up but right when his finger touched my butt he lifted his hand and kept it on my back. I hid my disappointment and said in a casual tone “Right, it’s all in the core and shoulders.” He didn’t respond but nodded. He then once again slid his hand down, starting right below my butt, over the thighs and back to the calf muscles, but this time, his touch was softer and he was moving his fingers over my yoga pants while his hand was moving along my legs. He was almost playing with me.
I was starting to get wet. I was also running out of breath and stamina. I then sat down and said “you’ll get there too.” I could see he was turned on. He was looking at my eyes but he was stealing glances at my legs. Everything went quiet for a moment. I said “next time then?” and he composed himself and said “Oh yeah, until next time.”

Source: reddit.com/r/gonewildstories/comments/108075k/f_i_42f_let_my_sons_friend_m19_fondle_my_legs