I kinda disagree, while I don't think someone should be actively and deliberately flirting knowing it was leading someone, I don't like advice that essentially tells someone they should pretend to be someone else (I'm not talking sinful habits here, I'm talking the essential person themselves). Jesus died for that person, love is about loving a person not a pretend act, and the idea that church is a place where we have to pretend and hide who we are, that we can't be honest with each other and support each other is disturbing in some ways. I think to many times we don't have the kind of honest fellowship we need, and instead pretend, to be what we think others think we should be, to be accepted, but as Christians we accept each other and encourage each other.
And it becomes difficult to determine what friendly action will someone else take as flirting, some men (I assume it's true for women to, but this is a woman feeling she has to repress who she is with others) can take anything as a sign of being flirtatious sometimes sadly. You can't live your life in fear that something you do that is just being honest, welcoming and friendly could somehow be construed as flirtatious such a smile or having a conversation with them, the men have a responsibility to be in control and not make assumptions about other people. I mean, you can go crazy if you had to analysis every thing you might do or say, just in case someone takes it the wrong way, because unfortunately that can happen anyway. And the idea that someone can't express the kind of person God made them to be, ie an outgoing, friendly extrovert for instance, particularly that we can't be who we are in the church, the family of God is just wrong to me (again this isn't about deliberate sinful behaviour or people using this as an excuse, rather it's the idea they have to pretend to be someone who they are not all together). To me this isn't putting aside her ego, it's having to put aside the person she is, the one God loves, in case someone takes something innocent the wrong way (which could happen anyway in some cases, people can be weird).