@Reyaj you're extrapolating 'principles' from bad game, over a tiny sample size. And I don't mean this as an insult, but let's look at this convo:
You open with straight intent (that's socially uncalibrated). She's 19. Ya, she's single--if she isn't it's not a serious relationship and isn't worth worrying about. This approach
can work, but you have to have frame, which you immediately give up by letting her steer the convo logically
before you even make an emotional impact. Then you
apologize for showing intent lol.
Refuse to entertain anything logical until after you've reach a social or sexual hook point, indicated by compliance.
Logically, she should
not be attracted to you. You don't fit in her frame. She can't take you to a frat party. Her friends will judge her. Etc., etc. So you give her an easy out by forcing her to weigh her whole social value in that frame against a total stranger who has done exactly nothing to demonstrate value.
You try to qualify her before she's done anything to show value (asking about her relationship status). That
can work, again if your vibe and frame are 100% on point, but it's low probability. You are 40. She is 19. If anything happens, it'll be because of
sexual attraction instead of
social value. But asking about her relationship status frames things in a societal frame from the open, where you're going to lose 9/10.
The fact that this felt weird to you is an emotional YOU created. Those are YOUR feelings. If she felt weird, it was because YOU FELT WEIRD ABOUT IT AND IT WAS COMING THROUGH YOUR SUB COMMS.
In this situation, I would've just opened like you were a social dude, throwing in a lot of little pushes and disqualifications:
Hey, I haven't been here forever.
(Low pressure--it gives context to your approach that doesn't force her to make a decision) What's your name? (Social--that's cool there's a frame for this interaction) Oh, cool that's my little sister's name. (Push--Wait, what does that mean? Am I not attractive to him?) Show me around for a second. (Dominance/Asking for compliance--chance to redeem that push) Are you studying to be a bank teller? (Push--she'll have to qualify and will try to clear things up) You're not married are you? (Spike--unexpected and breaks up logic) Cool, I was chilling with a girl one time who didn't tell me she was married and then he got all butt hurt and wanted to fight me.
(Disqualifying yourself as trying to date her or something weird).
If she asks you your age, just exaggerate it obviously.
I'm 17, but I have my older brother's fake. And then when she says you're lying, exaggerate in the other direction, say you're like 65 and here for the free senior citizen classes. By the time she get your real age out of you, the whole logic behind the question has already been stretched and, well, 40 isn't
that bad.
Keep experimenting with it bro. You need to be comfortable with an age gap before you can expect anyone else to.