cousins wedding in the cotswolds and a couple we've played with are guests. i nearly dropped my prosecco

absolutely did not see this coming. we're at my cousin's wedding last saturday, beautiful venue near stow-on-the-wold, and i clock a couple across the marquee who we met at a meetup in birmingham last spring. we've had drinks with them. and... other things. turns out the wife is my new cousin-in-law's sister. what are the actual odds. we did the polite nod thing and i swear my husband's face was crimson all through the speeches. they came over later by the bar and were absolutely lovely about it, very discreet. but how do you process that? we're probably going to see them at every family christening from now on. is there an etiquette i missed in the orientation handbook lol