Sex Talk

So we have all boys. Oldest is 8.

When should the sex talk happen? Everything is penis, buttholes, & buttcracks. Our oldest said he wrapped a piece of air dry clay around his penis to see how much he could get until there was none left. He also noticed my boobs bouncing as I did a dance outside & now randomly he says “mom go like this! Jump!” so he can see it again. It’s funny but also, we have boundaries & lines…so when should we have the big talk? How do we start talking about it? All of our friends are at co-op and also homeschooled but some are older. So I wanna get to them before they do (mainly our oldest)