Where do I put my hand when a girl is holding on to my arm?

I've never really know what to do with my hand when my girl is holding onto my arm. Its like do I put it in my pocket, open hand and place it on stomach, thumb in pants pocket... I don't know please help its very ackward and I like my arm being held and I want to be more comfortable.
Updates
+1 y
Thank You
Where do I put my hand when a girl is holding on to my arm?
Post Opinion