I have a 1 1/2 year old german shepherd, unneutered male. He follows this fixed female cat of mine around the house and just stares at her nonstop. He will just stop what he's doing and follow her, he never acts aggressive or anything, he never goes up to her, though she comes and rolls on her back and rubs on his face and such. She's kind of a fraidy cat and usually sort of stays away from scary situations, but she isn't super upset by his following her. He just walks around the house, she will lay right next to him, but it's just a little weird how he acts toward her. Anyone know what this behavior may mean?