Constantly touching gf's breasts

I love the way my girlfriends breasts feel and I tend to touch them a lot. Usually it's just as simple as sliding my hand under her shirt and bra when we're sitting together on the couch, if we're watching a movie or reading, or cuddling in bed, or just at some random point in the day. Sometimes it's a playful squeeze or sometimes I just like resting my hand there. She doesn't mind, and actually likes it. I don't ignore the rest of her body by any means, but is it normal to touch her breasts this often?