Bells and whistles aside, can we talk about the fact that it’s pretty much canon that Barry and Iris are married? In every way it truly counts they considered themselves married.
Iris said her vows in the wee hours of the morning of the day she was fated to die because she didn’t want to leave this earth not being Barry Allen’s wife. So, even if it were never legal, in her heart she was Iris West-Allen.
Before Barry walked into the Speedforce Iris told him she wanted to be Iris West-Allen and he said, “you are, and you always will be.” Even though Barry didn’t say the customary vows the way Iris did he still made it clear that he viewed her as his wife. That in his mind she belonged to him just as much as he belonged to her.
Again, it wasn’t legal and there wasn’t some huge celebration marking the occasion, it was just two people who knew in their hearts that they belonged together. It wasn’t for anybody else to know, it was just for them. He’s her husband and she’s his wife.