So lets say they get married what then. Batman carries on batmaning but what about Selina? part of the reason why Harley eclipsed Selina is that in recent years they've turned her into love interest not a solo carrying character. If Selina isn't thieving and cating around then what is she a good guy?
Her position is so murky that i'm not sure where she stands now. She's definitely not the Selina kyle of old who always had her own personal agenda. Poor cat has been declawed.