Well, for a layman, I have always thought that since a sociopath lack the moral judgement for right or wrong, that they lack the intrinsic ability for empathy much less love.
Before you ask, "Huh?" Hear me out.
To tell the difference between right and wrong, we have to be able to put ourselves into that person shoe. Not the decision we will make base on that but what we are able to perceive what the other person is going through.
Anyone able to watch those monster beheading another person and not feel at least queasy about some unfathomable thought or feeling are true sociopaths. They don't understand what the big deal is. The people doing the beheading, although are monsters in their own right, are also not sociopath. They know the difference between right or wrong. They have just accepted that it is their right and moral obligation to commit such deeds.
If you were to ask a true sociopath why they beheaded another human being, they would not try to give you an excuse beyond that they can so they did. If you were to ask those ****** why they did it, they would respond that it is their right and moral obligation under their religion and law to do so.
And since a sociopath cannot feel empathy, they cannot love. They can lust and posses but the give and take of a relationship base on love? No. For a true sociopath does not care about anyone but their self gratification and what they can take and posses. They have nothing to give in return for unless it benefit them in someway, they are not able to care enough to try.
Those that are functional sociopath with relationships and families has learned what most prey hunters learned. To be successful in a hunt, you need to blend in. Camouflage yourself among the prey so you can pick and choose the best prey with the least amount of effort. For that is all we are to them, prey.
TL:DR Although I doubt that the person you are talking about is a true sociopath as they cared enough to tell you that they are one and asked you to distance yourself, remember that true sociopath are prey hunters and to them, we are the greatest prey of all.