FTFY
The rest of you are making this wayyyyyyy more convoluted than it needs to be.
Picture this. You're a guy. You know a girl in middle school, lets call her Caitlyn, you and your best friend Mike always hang out with her after 7th grade classes. Caitlyn then moves away.
While flying back from vacation once, you sit next to this gorgeous 19yo girl on the plane who starts to flirt with you, and also looks somewhat familiar. You figure it out after a bit, it's Caitlyn, your friend from down the street. You figure, what have you got to lose - and invite her back to the bathroom.
Now imagine other people characterizing this as "you let your own hornyness take control". Huh? You wanted to get with the girl you knew from middle school who's all grown up now...
I wouldn't have a problem with that, but there's a couple of things missing like lying and misdirecting to "Caytlin" and your friend to hide the situation.
Btw you suspect your friend carries a major torch for Caytlin, and that's the main reason for your sneaky attitude.
You can't do those things then have a "woe is me" attitude, "i just love too much" and be sympathetic, at least not to me.
And the game doesn't offer many options here, either not talking to her ever again or swallowing her bullshit wholesale.
you call it "incosistency" but what you describe is quite consistent.
a girl who has a crush on a guy for 5 years and when she find him after all these years she have casual sex with him.
a girl who has (fighting) with the best friend for a boy's love stole a kiss from him when she was young and later takes advantage of a situation to have casual sex with him.
now you say she is a horny girl but from what i saw she is only a horny girl in relation to the MC.
about the changes in the way she talks I can't say much because I've never done a Lexi full path. but i say people acting all dumb and stupid is quite normal in the early days of a relationship when everything is still wonderful
you may not like her but she seems to be pretty consistent for me. but as I said I've never done a Lexi full path so feel free to correct me if i said something wrong.
The inconsistency is the later portion, i had no problem with the "fun girl" Alexis falling in love.
The 5 year crush over a stolen kiss was later dropped into the story as a way of justifying "why would she risk lying to her friend over a guy she just met?", which i also found weak given that they never seemed to have a close relationship (he barely remembers her and was completely blank on the kiss).
Other than that it's what i wrote to the guy above, her actions go beyond the basic taking advantage of the coincidence into dishonest territory and her attempt at "owning it" sucks.
And your only option is eating her bullshit (or ignoring her forever).