>>93172687I agree with this.
To me it seems like the best course would be to have them get married, move in, then both of these solitary people gradually realise that living together for the long haul is a hell of a lot different than fucking on rooftops in costume. Neither of these people is great at relationships, and neither of them is likely to be keen on couples counseling; and you can almost never have 2 people like that getting married without it causing major problems.
So once the glitter wears off, he'd start getting bossy because he's not great at sharing his personal space. She'd get pissy at his attempts to be controlling, and they could lapse back into how their relationship was before as relationships often do. They'd start growing apart, and Selina's old ways would reassert themselves as she realises that having shiny stuff just handed to you lacks the joy and excitement that stealing it brings. She'd start stealing again, Bruce would get pissed because muh justice etc. He'd give her the ultimatum to give up stealing forever or gtfo. She can't not be who she is, so she walks out. Both end up more emotionally scarred and their habits even more stubbornly entrenched than before.
It'd be realistic, would reestablish the necessary tension between them with no need for a reboot, and could be handled in half a dozen issues or less.
DC'll never do it, or they'll do it in the dumbest way possible.
TL;DR I think they should get married and divorced but I'm not holding my breath.