While yes males do make them, occasionally some females will also. Also, making bubble nests is associated with the betta's current state of mind, but it doesn't necessarily mean he is unhappy if he isn't making them or that he is happy if he's making them. Either way if he's noticably healthy and is making his nests, then I would totally say he seems happy. Since you already know that bettas make these nests for breeding, it doesn't mean that when they start making them they must be bred. Anyway, best of luk with the more continued happiness.