Wanted an opinion on this. I know passing them raises your value, but if the goal is to get laid are there times when you should tell the girl what she wants to hear?

I blew it with an attractive girl, problem she is very insecure and has low self esteem. I got to know her for a couple months through friends. She flirts with guys for validation, even older men. She puts up ass photos on instagram and all these horny dudes comment on it, she replies "aww thank you" with love heart emojis etc.

She only just started seeing a guy and they are exclusive which means I blew it with her. I also didn't validate her apart from a couple times. I'm not a fan of acting cutesy, like a couple and needy with a girl I haven't even hooked up with yet and she was trying that. Anyway with me she threw some big shit tests I felt I handled well enough.

1) Telling me about the other guys interested in her and how she turns them down. This happened on 4 occasions, I just looked at her blankly and said cool. One time she said "ugh guys are pigs, this guy at the club grabbed my ass and asked me out". I looked at her and started chuckling, the look on her face you should have seen "what, why are you laughing?" and she hits my arm.

2) She saw me and out of the blue says "hey___ if I find you ever cheated on or broke a girls heart i'll fuck you up" and I just looked at her. I did not answer and deflected asking why say such a thing and she trailed off into a lull in conversation.

There were other shit tests but these were thrown at me dealing with her insecurities. I think she was really on the fence about me and settled on this other dude. I do not put chicks on a pedestal but maybe I should have with her if I only intend to bang?

I was wondering if you guys have any experience handling girls like this and what you did? i'd like learn and build on this experience for the next time.