Shadow is brooding, mysterious, and quite rude to others. But, not to you. Of course not to you. How could he? You're his wondrous, innocent girlfriend.
Sure, he doesn't know how to show it like a normal person, but he loves you. He would do anything for you. He gets incredibly jealous when he sees you talking to Sonic. He would get even more jealous if Sonic were to wink at you, or put his hand on your shoulder. Shadow would always hide his jealousy, of course. He doesn't want you to worry. To cuddle, he would just hesitantly wrap his arms around your middle, (despite being taller) and fall back onto the couch/bed, laying his head in your chest. You didn't mind, of course. He was very awkward, to say the least. He really had no idea what he was doing.
Shadow knew he wanted to spend his life with you. He would do everything in his power to keep you safe. He won't let anything happen to you, like. . . like what happened to Maria.
It was sad, however, that everybody else thought that Shadow was trying to use you to get to the Chaos Emeralds.