Okay! This is how i imagine their first time to go.
(There’s a lot of backstory and like, basically an outline of a fanfic at this point and like, leading up to it. A LOT, I’m so sorry, I got overwhelmed with all these feelings)
I think Lena definitely has not had Good Relationships? And who knows why (apart from her being a Luthor) but maybe it was something like this:
Headcanon for first time?
Published
Question of Smoke 