Sibling Love

I have just been so overcome with joy lately with how much my children love each other.  They enjoy playing together.  They make each other giggle.  They just have such a great time when they're together.  I will often see them hugging, reading together, or helping the other clean up toys.  I am just trying to cherish each of those moments before either or 2 things happen.  Number one, I know that baby brother Keaton is going to upset the applecart soon.  I hope that that doesn't cause increased sibling rivalry.  Number two, I know that there will probably come a day *sigh* when they annoy each other more than they amuse each other.  The sweet innocence that they share right now is just absolutely PRICELESS and I wish that I could capture each and every moment. 

Last night, they were taking pretend pictures of each other with a toy camera in Cassie's room.  I heard, "NO, Conrey, I'M supposed to say cheese!  You're taking the picture!"  He was behind the camera, looking through the hole, saying 'cheese.'  She was giggling like crazy at this. 

In the bathtub today, one would shriek and they would both burst out giggling.  Then, the other would try to do a more funny shriek and face and they'd bust up again.

How do you bottle this sweet, sibling love to pour over them when they're adolescents and cannot stand the other?  I want to keep the kindness, love, patience, joy, etc. that is between them and never let it fade. 

I know that it is possible.  I've seen it in action.  I just want to figure out the secret and instill it deep within their beings.  Right now, all I can do is encourage their playing together, their laughing together, their sharing.  Oh, and smile a deep grin of mommy contentment.  That, I can certainly do.