Welcome Nueva Gal!
I love MomtoAD's suggestion about starting with the drink sharing! Great idea - I've told my son that forever, but never considered using it to segue into the kissing conversation.
I started the kissing conversation with DS back when he was about 10, and kids were already starting to pair off in elementary school (actually, I remember that being a big pairing off age, even back in my day - you know, when dinosaurs roamed the earth). All joking aside, I guess some of it depends on how old your DD is.
I know I read something recently about how long you have to refrain from kissing, but I don't know how long that is. Honestly, since they see each other at school the chances are they will be running into each other spontaneously - he should probably refrain altogether as long as they are a couple.
Possible TMI
And not that you want to even go there now, but if and when she becomes sexually active, condoms are going to be her best friend in more ways than one. Seriously, those proteins can be passed via semen too, and there is definitely a longer window period than with kissing. Just sayin'.
As for training him on the epi, honestly, that's probably the easiest thing about the whole situation. I like the blame it on the parents scenario, if she really feels awkward about it.
Honestly, I feel so badly for our kids wrt dating. Dating can be so anxiety provoking without this extra layer of awkwardness, KWIM? I know DS's first girlfriend was super-careful, but they had known each other well for about a year before dating. I have no idea what's going on up at college; I can only hope he's using good judgment.
Serenity now, serenity now, serenity now...