I 26 [F] Indian – Felt my cousin 21 [M] grinding his thing on my Ass!

I can’t believe that it happened but the fact it turned me on scares me even more. It happened yesterday’s afternoon when I was trying to sleep and he came inside my room (for what reason idk). I was only wearing a loose top and shorts as summer season is already here in India. He sat beside me (I heard him but didn’t respond as it was usual for someone to come and sit and i was trying to sleep) and the next moment, i felt his hand on my ass. I was thrilled and tried to scream but i still don’t know why I didn’t react which he took as a confirmation that I was sleeping. I was lying on side and moments later, his thing was rubbing against my ass. He was grinding it slowly but i felt that he was hard. I couldn’t even move a bit and he kept doing that for a minute. I was shivering on inside but it turned me on. He suddenly stopped and left the room after sometime. I couldn’t believe it but i was wet and horny. He’s acting like nothing happened for now. I don’t want to tell someone but having a thought of what happened is turning me on again and again.