a home bird
One who prefers the comforts and familiarity of one's home to new and unknown places or things. She invited me to a party with some of the cast members from her play, but I've always been a bit of a home bird, especially when I don't know the people I'll be hanging around. Our daughter has always been a home bird, officer—being gone for such a long stretch without at least making contact with us is completely out of character.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
a ˈhome birda person who spends most of the time at home because they are happiest there: Sheila’s a home bird really. She likes to spend her free time around the house or in the garden.
Farlex Partner Idioms Dictionary © Farlex 2017