Is it normal for young chilren to continue as sex buddies?

When A friend of mine and I were young children his little sister slept in the same bed with us. as well as took baths togeather.
Westarted notacing the difference.
We did not stop her from playing with what we had and she did not doto us from our exploration.
Things soon became oral.
Now 30 plus years my friend and I have continued oral activities and what it led to when we were pre teen,
Its better than ever. Is it normal? Would you and your friend continue or stop or females would you continue enjoying.