I need advice don’t judge please

Okay so me and this guy are friends and we have been for a while and I like him sooooo much but he has a girlfriend so I’m not acting on it but today at school he texted me to leave class and meet him I did and we were walking and he grabbed my waist turned me around kissed me and walked away idk what to do I like him so much but he has a girlfriend and I kinda want to tell her Bc I feel bad but then I would ruin me and him being friends I want him to leave her 🤦‍♀️ he said he wouldn’t Leave her Bc he loves her and I said if you loved her you wouldn’t be talking to me and he said I’m sorry but then he goes back to saying things idk what to do help and please don’t judge or be mean