How to handle the future awkward "TALK"?

I was hanging out with Ben and Shell yesterday and he and I ended up having a conversation that is leaving me feeling so unclear! LOL Warning, we have some terms in here...don't be offended.

I told him that my sister who is 15 was doing her art project and asked my sister and I for our opinions before she added finishing touches. She had a glittery gold ball in one corner with a squiggly line attached to it. I asked her what it was and she said a cherry. I told her she may want to add another cherry attached because it kinda looked like a sperm, which my other sister agreed. (I know blunt and maybe uncalled for but better from me then rude HS kids)Well she looked at us puzzled and asked "Sperm?" and I'm like "Yeah, it kinda looks like it" Then she looked at it for a while and asked "What's a sperm?" Sara and I both starred at her waiting for the joke to come clean, but she seriously didn't know.
In her defense, Jennifer missed the whole sex ed session in 7th grade when we went to my grandad's funeral. We were gone for about 3 weeks, so she missed everything. My mom didn't find out until way later. So now and then Jennifer is completely lost when it comes to very basic knowledge of the whole thing. Not to mention, if you meet her you'll find the most pure-hearted girl! She is an amazing example, so she feels awkward about the whole thing anyway thanks to our corrupt world. But she's not sheltered either, so it was interesting.

ANYWAY...I'm telling Ben this and asked him if maybe I should bring it up to my parents since Jen asked me to give her more of a low down. But I wasn't sure if it was my place...but he cut me off and here is our conversation. (We ended up in tears of laughter throughout in case you're wondering if it was angery, it wasn't)

Ben: "No, I think she's fine not knowing about that yet, I wouldn't want Michelle knowing about that stuff at that age!"
Me: "....at 15 Ben? Seriously?"
"Yeah at 15! Thats way too young to be learning about that stuff!"
"But they teach you about it in 7th grade! You want us to sign that form saying we don't want our kids to participate?"
"Well, no they can learn about it, I just don't want them knowing those terms!"
"Sperm? You don't want them to know what that is in high school? Its science, its part of life! If they don't learn the basic situation by then, only a few years later they'll be married and completely scared!"
"No they won't! I just don't want them knowing words like...like...penis and sperm, well I guess Michelle can learn vagina since she has one...But I don't want to say (he repeats other words that aren't curses but not clean either)"
"I would never teach our kids those words! Or tell them those things are ok to say! But those aren't the actual words they're taught in school!"
"Ok..(he starts laughing) well...still!"
"So if her friend says "Michelle don't see that movie! It shows a man's penis in it! Its not a very good film! You would want her to not be friends with that girl?"
"No! Not if she's using that word around her!"
"And if our son comes to you and says, Dad I woke up with wet pants - you are going to say...?"
"I don't know! Pray about it?"
"Ben!"
"I guess I'd say you're just having a woody and when that happens..."
"Ben! That not a good term!!! What are you doing!?"
"Well I don't know!"
"Ben....think back to when you were 15."
"Ok.."
"And your friends Jon, Jrod, those guys tell you! Dude!!! Someone drew pics of sperm in the bathroom stall! That was so wrong! And then you say "Guys? What are you talking about? What is sperm?" You're saying they would understand and move on?"
At this point we both burst out laughing, but he stays on his course.
"I wouldn't care! I don't want our kids finding themselves in situations that surround them with that kind of talk."
"Ben...are you seriously asking me...right now to home school our children?"
"No! Not at all, I don't want them sheltered!"
"Ok because you know that no matter where they go, unless I lock them up in a room with tape around their eyes and ears, they're gonna here about sex from kids. I found out most of the most disturbing things on the bus...to ELEMENTARY School! But I knew I could ask questions, and when I learned about it at the right age things became less disturbing as I got older!"
"Well...I...its...not good Rachel."
"Ben, its also healthy for girls to know about their body!
"The church says not to masturbate!"
"You fool!!! I didn't say that!!! But girls are asked to do breast exams, and to at least have a look now and again to become familar, so if something comes up, they'll know to aleart a dr! It can help stop diesease and things before it gets worse, heaven forbid!"
".....ok."
"And hello! We're also its wrong to "touch" children, but that doesn't mean we can't change their diapers or give them baths, babe."
"True..."
"And girls to have an idea about the opposite sex. If we have a boy and Michelle sees us changing a diaper and asks whats up with those different parts...what are you going to tell her?"
"That's his pee pee"
(I'm laughing so hard at this, tears start to form)
"Ben!!! pee pee is what we tell Michelle when she goes #1! Don't you think she'll get a little worried if she thinks her brothers pee pee looks like that!!"

We laugh for a good long while and after I calm down I say,

"We need to get our act together, babe. Because that day will hit before you know it and we need to be on the same page. I want us to be comfortable with our kids talking about something so improtant. They need to get it from us when they need to know, not from some punk kids."
"If they get comfortable talking about it, they'll want to go and do it!"
"Not if we instill the right values in our home, they need to be educated in both ways."
(He stares off for a long time.)
Me:"So to double check, you don't want our kids knowing let alone saying sperm and the other scientific words that our connected with reproduction?"
"I didn't say that..."
"Uh...Ben?"
"Ok I did, I'm just freaking out! I want our kids to be like your sister, completely in tune with good morals, but yes I want them to know that stuff...I guess too."

We still have to get some common ground together, which I know will happen in due time and that with guidence we'll be fine! But it was so interesting to see how it is being two young parents totally lost in something that we've been through as teens, learning about the birds and the bees! LOL Any advice on how your converstations have gone with this topic would be greatly appricaiated, LOL!