we exchanged kik usernames with a couple at the club at 1am. its been 3 days. who messages who first

genuine question and ive googled and the answers contradict so im going to the source. so saturday night we met this couple, conversation was easy, no play happened but it was clear we both wanted to see them again. at the end of the night we did the kik exchange dance, both couples saved each other, said good night, left. now its tuesday and the chat is empty on both ends and i cant tell if the etiquette here is "the couple who initiated the convo first messages first" or "whoever isnt the man messages first" or "literally just message them dont overthink this." f39 he 42, married 13 yrs, lifestyle 4. this isnt our first contact-exchange but we usually meet ppl through events where theres an obvious next step. cold club exchange is newer to us bc we just started going to this particular club like 6 months ago. oh and also btw, the wife of the other couple was the one who put HER kik on MY phone (we did the swap by handing phones across). does that mean shes expected to write first or does that mean she expected ME to since she did the handoff? im reading tea leaves at this point i know. is 3 days already too late. is a week ghosting. whats the actual unwritten clock on these