In Batman #24, Batman proposes to Catwoman on the last page. After meeting his father, Thomas Wayne, in the mini-series “The Button” he starts having second thoughts about being Batman. His father even told him to not be Batman. He wants his son to enjoy his life.
This is not the first time Batman has tied the knot (or come close) in the comics. On Earth 2 he actually did marry Selina Kyle and their daughter became the Huntress.
He nearly married Lois Lane. Lois believed Bruce Wayne was actually Superman. That had to make for awkward meetings of the Justice League.
He had a close call with Vicki Vale as well. She was kinda politically trapped into marrying a visiting Shah in order to keep the peace. Vicki said she was engaged to Batman already. When Batman told him Vicki would have to undergo reconstructive surgery to hide her identity since Batman’s enemies would come after her, the Shah relented. He didn’t want anything to change her beauty.
There was an issue where Batman married Batwoman, but that ended up being a dream Robin had. There is another issue where Alfred writes a story where Batman marries Batwoman. They retire and Dick Grayson becomes the new Batman and their son becomes the new Robin. I’m actually surprised they didn’t use this story in an alternate universe issue.
There was a story where Eros gave a love potion to both Wonder Woman And Batman. They were all set to get married until they used the lasso of truth to break the spell.
The one marriage that is legally binding is to Talia Al’Ghul. Ras had Batman in a country where the only requirement for marriage was for the father and bride to agree. Therefore, Bruce Wayne is legally betrothed to Talia.
One interesting thing that may come from Batman marrying Catwoman is how will Damion Wayne react. Catwoman would than be his step-mom. Damion is surly and rebellious enough as it is. Adding this new wrinkle may push him over the edge.