School starts talking about it at about 10 for me.

Personally I never had the talk with my parents. Just school, friends, and pop culture.

Better to prepare them than to have to live with their mistakes starting in their teen years.

I would never do a first talk older than 13+ and I would always have condoms available. They need to be aware. I will also be discussing queerness with them from an early age.

13, though make it explicit that there are a lot of consequences to sex. Not that it's a bad thing, but only to do it if you're prepared for the risks

I don't think it does any damage at all for kids to know about safe sex and sex in general when they're on the younger side. Sex isn't dirty or wrong. If a teenager is going to make the decision to have sex, it better be coming from an educated, positive, and SAFE point of view rather than the not so awesome, misogynistic garbage we're exposed to through peers, the media, etc.

I picked any age. Just like puberty everyone starts at a different age.

puberty, because before then the kid's not going to be thinking about that stuff. I hit puberty at 8 and my mom was entirely open about any questions i had, but i never got the talk, it wasn't really needed. I just sort of.. knew?

Teaching about sex at any age is appropriate, as long as its at their level of understanding. Kids need to be prepared, especially in this age of technology.

puberty is generally the right time although sometimes it depends on maturity level or what is situational. I would go with puberty though.

15-16 plus.

I feel like any age between 13 an 16 would be ideal.

If they asked about it, I would have the talk at any age

Any age, i wish my parents had explained things to me.

I think any age where a child/younger person is understating of their actions and that every action will have a consequence is a mature enough age for them to be getting the "talk" along with protection. To be honest many of your tween's peers are already having sex, and they may be interested in knowing about it for themselves so it's important they understand safe sex and consent - i know many of my middle school peers were already engaging in sex, yet we were not taught much in the way of safe sex/consent/how to use a condom/ect. Many of my school aged friends were not well informed on how sex works or how to be safe, but still had sex (usual unprotected), and this was less than 10 years ago so i can only assume things have not gotten any better.