The two characters are about 15 and 17, respectively, and it's a first time for both of them, and neither have very much experience before this of anything more than kissing, and not much of that. It's very spur-of-the-moment situational (at a forest camp site, actually), and while they've known each other for a while it's not been on the best of terms so they're not even really sure if they like each other when all is said and done, but they're both kind of emotionally vulnerable at the time and very caught up in the moment.
you are going to the special hell for that pun!