Not once did we collude or soft-play each other. On the other hand, I used to play with my now-ex with some regularity, mostly in tournaments, and we even had an agreement to split winnings (I didn't love the whole arrangement, but that's another discussion).
None of these folks were related, as far as I know. Two players cap the betting in O/8 with nothing but flushes on a paired river, apparently thinking they could get my to fold my boat. 'Oh, sorry man, I wouldn't have bet that, but there was still someone else in the pot.' Raising off of each other and then one of them checks down a strong hand and the other a draw after everyone folds. I've honestly had more problems with friends and buddy-buddy regulars playing questionably with each other than spouses or relatives.
