Once I got to college and had my fair share of boyfriends that I was less than serious about, I had a method to dumping them. I was in a particularly demanding academic department and I usually had 2 jobs and a couple of activities that I kept up with, so for as long as it took, I would always be busy and tired and have my mind on something else. I was always very apologetic about it. "I'm so sorry- I know you wanted me to go, but this is due tomorrow, and I've had to work 2 shifts today so I couldn't even look at it yet. I promise you'll have my full attention for 2 hours tomorrow night." I'd keep my promise, but fall asleep on his couch during our time together. I was very patient with this, as it could take weeks, but it was worth it. Ultimately, they would decide to break it off (because I wasn't much fun as a girlfriend), and they'd always feel really bad about it since I'd obviously been trying so hard to be as wonderful as I could be.I think this shows an interesting adaptation of the female sociopath. The female needs to seem emotional (even better needy and weak!) to fit into society, so the female sociopath pretends to be these things in order to not stir the pot needlessly. A female sociopath in a relationship, unlike most male sociopaths in relationships, would also be physically less dominant than her partner. This might make her even more careful to avoid hard feelings, so as not to provoke a physical attack.
When they did it dry-eyed, I'd cry just a little (even pretending to cry makes me feel...beneath myself) and do the whole, "but I really like you" bit. They'd then take my hand, put they're arm around me, etc and explain that they liked me too, it just wasn't working out, blah blah. I'd act like I was being all strong and conciliatory, and accept with an "I understand, (*sniff* *sweet-innocent eyes*) can we still be friends?" Always a "yes".
If he cried when doing it, I would hold him and be the most wonderfully understanding person. "I get it. You are probably right. I just can't be a good girlfriend right now." "No- you are a good girlfriend, I just-" "It's okay. I'm right here- you don't have to be sad. If you want to see me, just walk the same two blocks you did today and yesterday. We can still be friends, right?"
Then, the most important step...
I'd tell one very big-mouthed person in our mutual friend group that I'm sad, but I understand and, like a good girl-friend, they'd always say something disparaging about the guy. I'd stop her, very seriously and tell her that he is a really good guy blah blah. Then, if someone came up to me and asked about it, I'd say the same stuff- giving the appearance of a stiff-upper lip and utter respect for the guy. That crap always gets back to them. If I ran into them, I gave them sweet, sad smiles and was as nice as could be. And now, years later, they are super nice to me and always act around me like the are trying to make up for something. No hard feelings. Just useful ones. :)
I think female sociopath adaptations are fascinating. I really wonder why there hasn't been more extensive research on them, apart from the obvious reasons that they aren't in prison (the psychological world's equivalent of deep pockets) and don't seem to suit the sociopath stereotypes (confirmation bias).