No one, although, Sombra gets McCree very close to doing it.
As they begin traveling up to America, they have their close and tender moments but McCree always stops it before it goes to far. This miffs Sombra to no end, because she doesn’t see why they have to wait to be intimate but McCree is dead set on making love to no one but his wife.
After a few months of hunting monsters, Sombra just strips down one night and waits for McCree. He comes back to find her standing there and he nearly has a heart attack.
They then precede to argue while Sombra’s naked and McCree is hiding his eyes behind his hat. Sombra is accusing McCree of not actually loving her but McCree explains that he wants her as his wife, why won’t she just be his wife already.
Sombra exasperates by saying she can just marry them herself. This stops McCree still. She then goes on to explain that she is the high priestess, goddess and ruler of her own religion, they can get married through her customs, and it would be valid.
They end up getting married right in that random inn, speaking some vows that McCree is pretty sure is part of a dead language while dressed in feathered cloths very similar to Sombra’s dress. Afterwards, Sombra finally lets him slip this gold ring onto her left hand. Needless to say, they spend that night very intimately together.