Guess I'll add some thoughts. Solely for Siobhan since she's the most relationship focused char I have and probably the most developed. She was in a relationship with her Jedi master Adril (which was a melodramatic rollercoaster since they were both codependent and self-centred), which ended with Adril dying killing a Cthulhu-like monster.
Over time she entered a relationship with [member="Tegaea Alcori"] and eventually married her. Think they've known each over for 15 years by now. Started as friends with...benefits when Sio was a Jedi and Tegs a mercenary, become lovers after Sio joined OP, eventually married. For a long time they made a very good team, with Sio acting as her strong right arm. Their marriage has had its ups and downs, especially while Tegs was OP's leader, but always came through and it was good for both of them.
Recently they've been drifting apart while both running Firemane, with Tegs growing distant and Siobhan largely doing her own thing.
Things got complicated when Siobhan fell for [member="Mirien Valdier"]. To a degree, though not exclusively, this was due to them being Force bonded and in a way having more in common, what with both being darksiders with very similar views. Mirien saving her mind also helped a lot! This created an awkward love triangle, Casablanca style. Much soap opera. Sio and Tegaea are trying to get their marriage on track again. Time will tell how that works out!
On another, Siobhan discovered her motherly streak after adopting [member="Galina Kerrigan-Alcori"]. That was a very sweet story about finding the girl, who had been marooned on an abandoned island in the wilderness for several years as a kid. Later on adopted [member="Natoline Kerrigan"] and seems to be putting [member="Abaigeal E'ron"] under her wing. Yeah, blame Galina for getting Sio addicted to mothering. None of this was preplanned. Did not expect Sio and Tegs to get married, expected Sio and Mirien to try and kill each other during their first meeting. And until meeting Galina Sio really did not want kids.