"Slash Option: The Wedding of Batgirl and Robin" from Batman Family vol.1 #11 (DC, 1977) by Bob Rozakis, Curt Swan and Vince Colletta
An often-mentioned "slash option", but remains fan-fictional since Dick and Barbara never really sealed the deal even if they dated for a little while. This splash makes me think all superhero weddings should be conducted in tux and wedding dress versions of the characters' costumes NO MATTER WHAT. Where are the action figures from this?
As for Batman Family, it was a mid-70s anthology series mostly featuring members of Batman's supporting cast of heroes, with original stuff and reprints from older stories. Wiki informs me that it brought back the forgotten Batwoman from limbo and also introduced Duela Dent, who I thought was a much more recent character. The article also says Batman Family was a better seller than Detective Comics in its day and that DC almost axed Detective at the time, instead cancelling Family after 20 issues and giving 'Tec its mandate.