Mindlink Mates: Played straight as an available option for couples, using much the same cybernetic techlepathy that everyone else uses. Such links also generally are filtered – no-one really wants to be fed the entirety of someone else’s sense/physical-status data and narrative thread of consciousness, however close they are. And even given that, a lot of people have them removed in a relatively short time, too. Continuous mental intimacy’s not for everyone.
Another spin on this is the custom among some couples likely to be separated for long periods over distances involving considerable communications lag to keep partial forks of each other around, with or without sync or remerge.