[RiverBenjamin]

Let me summarize:

Been seeing this girl for a few weeks now. Things have been going pretty well, with increasing levels of making out each time we see each other. Last night, at her suggestion, we got together with a few friends for drinks. When we were leaving the bar, one of our friends suggested we (the girl and I) crash at his place... obviously so we could hook up there. At first the girl was excited about the idea, but then inexplicably, she flakes out and decides to get a ride home with one of her guy friends (definitely platonic, nothing more) who was there having drinks with us. It had previously been established by a mutual female friend that this girl is really into me, so what gives?

Haven't heard from her today, and this is a pretty serious flake out, considering the way things had been escalating. Do I play it ice cold by brushing her off? Should I give her another chance? It seems like there should be some sort of punishment for flaking out like that. Anyway, only been seeing each other a short time, so nothing really major invested in this chick.

[Lumiere]

A few weeks?!

Don't bother seeing her again unless its at a place where you can close the deal. Her place or yours ideally.

[charmer]

i cant tell why she is flaking...there are numerous reasons why girl (she) flakes..one of the worst is neediness of a guy.

and the best punishment of flake is ignorance !

[Roosh]

I don't consider this to be flaking. It's more resistance than anything, assuming you're not making needy mistakes.

Isolation + booze is the key. If she refuses to be isolated then she's not trying to bang.

[thegmanifesto]

"Isolation + booze is the key."

Actually, that is one of the keys to life.

[UgSlayer]

A lot of girls are ADD to the max. You can have their complete attention and think things are going well, and then they catch a glimpse of something "shinier and prettier". Then they will go for that. It's rooted in their biology. It doesn't have to be a guy. It can be the opportunity for more fun. Girls act on instinct and emotions. That is why learning when to pull the trigger is golden. For me, it took pulling the trigger too early and too late a number of times to finally get my calibration right, and it's not even right half the time. Just go for the gold every time. If you have enough game, the girls will let you make mistakes over and over, and eventually you'll fine-tune your sense in when to escalate.

To your specific example, I would agree with Roosh that isolation and booze work best. I would go balls-to the wall to close her.

Next time that happens, you could have invited the dude to come and hang out at your friends place. If he refuses, you can call him out on trying to steal your girl and cockblock him, but in a subtle way. Say something like "I understand, you are such a nice guy for driving her home." then look at her and say "You should really give him a chance. He'd probably make a perfect boyfriend. He's super nice". Platonic or not, he was trying to fuck her that night or at least cockblock you. Make him pay.