What Bruce and Howard have is full of uncommon emotions for the both of them. Mostly because neither of them are used to the monogamy game lasting longer than a month, or even a year. Howard's more used to it but Bruce tends to hole away in the Batcave when he can't wrap his mind around his feelings. And Howard's accepting of it. He's patient and expecting because he loves Bruce and knows Bruce loves him back.
Howard helps enhance some of the Battoys and in return Bruce makes love to him for the next three days. It's a constant rhythm of them bouncing ideas off each other and to say the least, their life is always interesting.
Nothing ever stays dull in the Stark-Wayne Manor.