Sucking on Finger

So, it has began--Kyler is now sucking on his finger.  It started with trying to suck on both fists at the same time and has progressed to this (see picture above)--sucking on one finger in the side of his mouth.

He actually more plays with his finger in his mouth then sits there and sucks on it.  He prefers his pacifier to just suck on, but does like his finger and fists a lot.