A nearby college hosts free concerts every weekend. I met up with a HB8½ female friend "K" who had beta orbiter "B" in tow. K's "with" a good buddy of mine, and I strictly adhere to the bros-before-hos principle, so I limit myself to mild-to-moderate flirting and PG kino with her.

My wardrobe for these occasions follows some PUA basics: flashy bright colors, straw hat that I wave to cool down between songs, some Mardi Gras beads, etc. Good band, great music, lots of pretty young things shaking their asses. The band went on a break, so we went outside to catch some fresh air. We came back in and B went to get some drinks. K walked over to me.

K: "I need your help."
me: Oh really?
K: "B keeps trying to rub up on me and gets a little too grabby. I've already told him a few times that we're Just Friends but he Doesn't Get It."
me: (lol) Are you surprised? He brought you here, right? You're dancing with him, right?
K: "Yeah but, like, help me out here!"
me: (it occurs to me that until recently I would've immediately agreed to her request) Say please.
K: "Pleeeeeeeeeeeeeease!" (she tugs on my sleeve)
me: Maybe. (cue sly grin)
K: "WHAT! Hey! I got you laid!" (true story, she introduced me to a cute friend of hers, subject of a field report I'm still collecting data on)
me: Yeah, that was last week. This is now.
K: "Come on! YOU OWE ME, BITCH!" (she punches me in the arm)
me: (eyebrow goes up) Oh, really? Well, when you put it that way, ABSOLUTELY NOT! (Grinning and shaking my head, I grip her by the shoulder and push her back)
K: "Fucker!"

Which is about when B came back with our drinks, just before the band returned to the stage and resumed playing. Pretty soon B is getting handsy with K again. She immediately moves away and starts dancing with me, and after a while she starts escalating things to PG-13: bumping, grinding on me, giving me some flirty eyes. B backs off and stands to the side when she's dancing with me. Occasionally she'd drift back over to him. At the end of each song I remove my hat and fan myself with it to cool off. Each time she leaned in, officially to catch the breeze, but for some reason her arm kept working its away around my back.

After the show we walk back to the parking lot. B starts his car and wanders off to piss on a tree.

me: Did you notice how every time you were dancing with me, B backed off?
K: "And did you notice how every time I was dancing with you, the other girls nearby were eye-fucking you like whoa? I think it was the hat."
me: The hat, my totally sick nasty dance moves, and the hottie grinding on me half the night. Yeah I kinda noticed. This worked out well for both of us. (the other girls at the show were mostly HB4-7 with an 8 here and there for good measure.)
K: "So next week then?"
me: Next week, and hell, probably the rest of the semester too.
K: "Deal!"

tl;dr: Hot girls make great wingmen. Don't agree to do anything for anyone, especially a female, unless you're getting something worthwhile out of it.