The idea of not taking her away isn't AFC mentality in fact it is the direct opposite of AFC mentality.
Scarcity mentality and the taboo of wanting what one can't have is what makes AFC's attracted to involved chicks.
They turn their attraction to involved chicks because they fear they cannot create options with single available women so instead they will become little orbiters and false friends to some chick in a relationship and bide their time patiently letting single opportunity's pass them by just waiting for their oneitis to get into a fight with her boyfriend so they can emotionally be there to rescue her right out of her panties.
Yeah the AFC orbiter may get laid out of this pitiful scenario and yeah he may even get a girlfriend out of it but what he also gets is the title of being the dredded rebound guy and once his newfound girlfriend's emotions clear up surrounding the ending of her relationship that you and she helped end with her previous boyfriend she will either go back to him or she will once her emotions have settled begin looking to branch swing to the kind of man that she really wants.
A guy that takes a chick like this has a low quality piece of work in that he got someone that has the low character of a cheater and he suddenly thinks he's a pimp because he's now getting some action from another man's girl but the joke is ultimately on him because she is using a guy like this for the emotional high, some ego repair and when she's got enough she will go and shop for someone she really wants because she never wanted this kind of guy. She never really got to know who the AFC was outside of orbiter and friend and so she views the AFC who does things like this as a friend even if she ends up sleeping with and being the guy's girlfriend for a while. The AFC who partakes in this is partaking in a massive self delusion.
He's got to get a grip, grow some balls, become a DJ in so doing and go after his romantic interests in the light of day where the single girl immediately knows he wants her and then decides whether she wants him based on his level of game as well her level of attraction to interacting with him.
This is a much more manly way of things than playing friends and biding your time for your opportunity to score a chick that would cheat on her man.