The F* word

Today Isaac asked me why the F* word was bad? 

This is how the conversation went;

Isaac: Why is F* a bad word?

5 second silence 

Me: Well, do you know how daddies and mommies make babies?

Isaac: They eat a lot, and that makes babies

5 second silence with me not trying to laugh 

Me: Well there is something else that parents need to do to make babies. There is a nice and crude way to describe that process. And F* is just a crude option.

Isaac: OK

There were no further questions. Either I totally confused him, OR I really did answer his question (for now at least), but I am glad it went no further because I don't know if I could have possibly made that leap from 'eating a lot' to actual details of  the birds and the bees.