Definitely! You need to drop him like a hot potato because he is bad news. If he was decent he wouldn't be pressuring you into having any kind of sex and yes oral sex is sex. You aren't legal and he should know better. Even if you were legal he doesn't even respect your wishes=you don't want to have sex.
The important thing is to cease all contact. What can he do back to you? You just go on with your life and focus on school, your activities and your friends. good luck sweetie
He's clearly a child molester if he is pursuing a 13 year old at the age of 20. Who knows how many other times he has done this to other kids. Child predators are morally reprehensible and should be arrested and thrown in prison for the rest of their lives. Do you honestly want to keep dating a child molester?
Yes, he is legally and morally too old for you. Sexual activity with him is not a good idea and of course he wants to have sex with you. All guys do. Check your state laws. You two would not be into the same things and shouldn't be. At your age it is simply too large of an age gap. I have a 13 year old child and while you feel grown up, please know you aren't. Said with motherly love. A 20 year old man is taking advantage of a young girl. Steer clear. And yes, he could get in trouble for pursuing a sexual relationship with you. good luck and study hard in school!