i once attended a JW wedding in my home congregation ( my dad wasnt there ). The authorised person wanted to see the -licence-? banns or whatever--?--but the couple had forgotten to do all that pre-nuptial formality. So the actual " tying the knot" couldnt proceed. But they went ahead with the rest of the speech--and we all attended the wedding reception--but the bride and groom each returned to their respective parents homes afterwards. The got a special licence and finalised their marriage a few days later.
I dont know if they stayed together.