Your sister's friend is what we call a "wannabe". She's playing a game for her own gratification and doesn't care who gets hurt in the process. Such selfish females behave with no conscience for what they do... they simply don't care.
This isn't a unique situation..... It isn't even unusual. Go into any gay club anywhere and you will see straight girls playing the wannabe game.
Some do it for attention, some even do it to make a guy jealous. There is still a little bit of a hangover from the 90's culture of "Lesbian Chic", where heterosexual women thought that dressing in an androgynous way, or adopting a lesbian dress style was "cool". Oh well, they say imitation is the sincerest form of flattery..!!
Some girls want to posture in a pseudo-lesbian attitude because they think it's chic, cool and has an edge of danger about it. They know they can walk away from it at any time and go back to their genuine heterosexual way of life, having had all the fun of the experience without taking any responsibility for their actions.
Such females are despised in the lesbian community, mainly because they help to create and promote the false notion amongst men, that lesbianism is a "lifestyle choice". These men may then harrass genuine lesbians in the false assumption that they are in with a chance of "curing" us. Hey..... I'm not making this up, it actually happens.
Some girls do what they do as a perverse way of "punishing" somebody who they know is lesbian. The rationale goes like this: (they think) "She's gay, So I am going to come onto her, get her all turned on and then back off at the last moment, leaving her disappointed and frustrated". Now, it takes a pretty warped mindset to adopt such a rationale, but again, it does happen.
I can't put my finger on why this girl is behaving in this way towards your sister, Giggles, but I would guess that the reason probably lies somewhere in one of the scenarios I have set out above.
Perhaps the next time she texts your sister leading her on, your sis should reply "Nah, you're not my type. I don't fancy you".
See what sort of response that gets....
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