in most fics i've read robin is grossed out when steve talks about his sex life, which is probably far more in character for her, but hear me out
imagine them discussing literally everything. like having no boundaries whatsoever.
one day robin mentions she's never seen a dick and she's curious what all the fuss is about.
when steve pulls down his pants, robin just stares at him with a blank face
steve: what do you mean that's it??
steve: ??? well, it's not hard rn, obviously???
steve: you want me to show you my hard dick?? is that what's happening rn?
steve: your judgemental face is forever burned into my mind. i don't think i'll ever be able to get hard again.
then robin bursts into his room like a week later
robin: steve, you're a slut-
robin: so you know your way around a vagina, right?? i need you to tell me if i have a rash or not
steve: do you not own a handheld mirror?
robin: i'm freaking out so much, i can't make a sound observation rn
turns out robin does indeed have a rash and steve takes her to the doctor
at one point they lose all shame. steve regularly air dries while robin hangs out in his room. robin makes steve do her monthly breast self-exam. they check each other for ticks.
when steve and eddie start dating steve tells robin literally everything. robin knows way too much about eddie and she loves it.
robin comes over for movie night, eddie is already there
steve: we slept in, then eddie fucked me, it was great-
steve: then we cooked lunch, there are some leftovers in the fridge, go ahead and eat. yours?
robin: ugh, don't get me started-
eddie: wait wait wait, how did you just say that so casually?
eddie: that i fucked you??
steve: i tell robin everything. i told you that. you said that's fine.
eddie: i didn't know that included our sex life?
steve: why wouldn't it? ... wait, oh no, are you not okay with that?? i'm sorry, i thought you knew??
eddie: oh no, it's fine! it just surprised me is all. y'all are real freaks, carry on
robin freaks out before her first date with a girl
robin: what if my vagina looks weird???
steve: are you planning to fuck her on the first date, buckley? and how many times do i have to tell you your vagina looks absolutely normal??
robin: no, i'm not, but it's still a valid concern!!! what if my vagina looks hideous to girls??
eddie, the silent observer: lol
steve: what are you even talking about... a vagina is a vagina, vagina lovers love all vaginas
robin: stop saying vagina
steve: vagina vagina vagina-
robin tackles him and they end up wrestling until steve yields
steve: okay okay,, as someone who's seen his fair share of coochies
steve: yours looks perfectly fine.
eddie: wait, you've seen it?
stobin, staring at him: ...
eddie: right, dumb question