In my personal experience, this tactical aspect of winging, the Occupy and Game the Wing to Prevent the Cockblock, is overrated. For the most part, the friend won't even care about the wing, and will do what she does (cockblock or not) independent of that; even if she does engage the wing, if she has a mind to cockblock, this won't stop her.
If the target is truly sexually available and truly likes you, and the friend has a basic understanding of this, then she'll stick with you and be open to your advances without issue. Your actions and strategies make less of a difference than you think, and what's gonna happen will happen, either decided on from the outset or apprehended in the moment.
If the target is truly sexually available and truly likes you, and the friend has a basic understanding of this, then she'll stick with you and be open to your advances without issue. Your actions and strategies make less of a difference than you think, and what's gonna happen will happen, either decided on from the outset or apprehended in the moment.