If you want to start family sex, talk first and just masterbate together.

My sister and I started as kids and it was awkward. We played cards and she said looser has to cum. I lost so I pulled my pants down and came. She then pulled her pants down and used mom's vibrator to cum. She squirted.

My daughter and I started last year. We talked a lot and then went in the shower together. We did the same thing, masterbated and came in front of each other. We did this for several weeks until we started oral and then sex. I think everyone should try family sex. But start with talking about it and masterbating.