Not canon, but in the TNG/DS9 relaunch crossover novels, Garak has a male life partner/husband, a guy about his age, iirc. I think it was in one of the "Typhon Pact" or "The Fall" novels.
Dr Kelas Parmak.
Referenced in passing in The Die is Cast as Tain's personal physican who was interrogated by Garak, leading to some time in a labor camp.
He and Garak encountered each while working with a volunteer medic unit after the Dominion War and they reconciled, with Parmak later introducing Garek to Alon Ghemor, the leader of Cardassia's fledgeling democratic movement, setting Garak on the path that would eventually led to a term as leader of Cardassia.
In typical Garak style, the exact nature of their relationship is unclear, however he's certainly one of the few people who Garak is emotionally close to, honestly confides in and respects, so while it's unclear whether they are married or even formally romantically involved, there is certainly potential there.