I need a bit of help figuring out how two characters would react to this situation.

ok, lets see...
well i read a book like this and if i do remember right they ended going out because they really liked each other(but u dont have to end it like that)
당신 can have a big event that leads them to do what they did. Afterwards they try forgetting what happned cause they dont want to ruin anything but the fact they like each other makes them go out 또는 have a fight about it. (its really up to 당신 as the writer but here's something your welocme to use. hopefully i was somewhat of a help ^.^)

They could end up ok with it and falling in love. 또는 they could regret it, and come to hate each other, and feel awkward.

They become boyfriend and girlfriend (unless theyre the same gender, then gf&gf, 또는 bf&bf)

One wants a relationship, the other doesn't 또는 vice versa

Theyre both embarrassed but either do 또는 don't want a relationship.

They pretend it didn't happen

1) They end up in a relationship
2) They pretend nothing happens
3) They fall in love, but they don't get into a relationship (I don't know, because there'll be a consequence 또는 something
4) One of them reveals a secret about himself/herself that will totally change the way the other feels
5) They decide that its best if they see other people

Well, this is what I think should happen:
They remain awkward for some time, but then one 일 they realize that they really miss eachother, so they have some epic make-out scene and they are dating

AWKWARDNESS. But eventually they'll talk and then fall in 사랑 또는 something.

It all depends on how it happened. They could become uneasy and akward with eachother afterwards, but if they thought and talked it through before it even happened, then they would start a relationship afterwards.

idk wat your whole story is bout but they could both have single parents (of an opposit gender) that end up gettin married an now the two 프렌즈 have to deal with that situation