It means that he is not your boyfriend.
Of course, this is all hinging on how long you have been dating, but just in general, if your man NEVER invites you to his home...and you know he has one? Something is awry in the state of Denmark. Or your state assuming you don't live in the state of Denmark, which is undoubtedly, NOT in Les Etas Unis.
You'd also be right to let your mind wander on outrageous flights of fancy. Is he hiding something? How would you know; you've never been to his place. Maybe he collects Barbie Dolls. Maybe its Stonehenge replica pebbles. Maybe he has an entire other life and family and you'd never because you always spend time together on your side of town.
Who knows. But they're very valid questions. When you are with somebody, part of the joy of getting to know them is to learn the things that aren't spoken. The learning that takes place just by being in their presence and seeing how they respond to stimuli. Part of that is seeing the environment that they're most comfortable in,, which is, or at least should be, their home. The types of pictures on their walls and the books on their shelves, the types of furniture...it tells you something. Anybody who has truly let you in will bring you into that part of their life.
All that to say, he's not your boyfriend.