When you are writing a contemporary teen narrator, please stop having them talk about "going steady" and "necking."
It's not that today's teens don't do these things. It's that they don't call them that. With their crazy teen lingo. And if you hear them do so when they're talking to you, quite often they are trying to translate for your benefit.
My cousin A was visiting when I was telling my mother that my young friend B now has a boyfriend. "And he gave her his [activity] sweatshirt, so apparently that's a thing," I said. "Oh yah, that's a thing," said A. "It's like when you were in high school and your boyfriend would give you his letter jacket." I had to explain to the dear child that I was not of that generation in the slightest. While one of the unsuitable boys I dated in high school did, in fact, have a letter jacket, if I wanted to wear one, we both felt I could certainly earn my own.
So. Returning to the point. "Going steady." "Necking." Please. Stop.