Not much to offer here.
I suspect that when you goofed up and realized your mistake, that you got P.O.’ed but then quickly channeled that annoyance to your girlfriend, she being the most available target (other than yourself).
The real reason I chimed in is I thought both situations in the O.P. were genuinely hilarious and I’d love to see the two of you in action. Let me know if you’re game for doubling up some time. 
I don’t point out to Mr. brown if I think he’s taking the wrong route for exactly this reason. Often, if we’re setting out for Costco, he may have plans to hit the hardware store on the way there and hasn’t shared this with me. Now I just keep my mouth shut. Sometimes he completely misses his exit because of this, and tries to hand me a ration of shit for not mentioning it. Damned if I do and damned if I don’t.
How did/would she respond to something off the wall like, oh I dunno, maybe something like ironing taffy? 
Would she step in at that point?
Unless you specifically appointed her navigator, I wouldn’t expect someone to try to correct my driving decisions. Maybe if you constantly screw up, can’t find your way out of the garage without directions, but if you are a fairly normal person why would she assume that you’re so incredibly brainless as to not know where you’re going?
I’ve been married for 12 or 13 years and I certainly don’t question every turn my wife makes, nor she me. “Is this the best way to go? Shouldn’t you be in the other lane? We’re going to A first so don’t go this way. You’re following too close.” - this isn’t my idea of a good way to live, but if that’s the way you like it, tell her - “Honey, please nag me incessantly to make sure that I never do anything that isn’t exactly the way we discussed it earlier.”
I think you’ve hit on one of the trouble spots in relationships. Of course you are expected to help your partner; you’re also expected to treat them like adults who know what they’re doing, and not nag them. I think the correct response to this varies with every single situation. Sometimes my husband knows exactly where he’s going and is taking a shortcut; sometimes he has forgotten something we added to the trip later and is going to miss his turn. Sometimes I need to say something, and sometimes I don’t.
If I see him making an obvious mistake (paying for something that’s free), he has obviously forgotten that it was free, and it would be mean of me to not say anything. Other times are definitely not as cut-and-dried. I think you should talk to your girlfriend about this, Cagey. Letting you pay for a bus ticket is different than letting you waste a whole bunch of money on something she knows is a mistake.
Sounds like you may want to discuss this with your SO instead of listening to a bunch of strangers’ advice.
Well… mine, anyway.
But if not, there’s always the old reliable Lawn Darts/Quicklime/Folding Shovel routine.
Did you think that with regards to the first incident, maybe she wasn’t paying attention? When someone else is driving, I may tune out or pay attention to the scenery as opposed to the road.
With the second, maybe she space it as well.
Ultimately you screwed up, being pissed at her for not catching it isn’t going to help and isn’t going to give you much sympathy.
So your actions were accidental, but her inaction was intentional.
Well, my goodness. I totally take back what I said before. You obviously are not prone to overreaction in the least! Seriously, you should know that here of all places, when you ask for opinions on something, you’re going to get 50 different opinions and half (or more) of them aren’t going to agree with you. That’s no reason to go live in a cave by yourself singing “Nobody likes me, everybody hates me, guess I’ll go eat worms.”
And no, relationships haven’t degenerated to the point that we’d rather laugh at someone’s fuck-ups than try to prevent them. It’s just that people are sometimes thinking more about what they’re doing than what you’re doing, or as has already been pointed out, thought you knew what you were doing. A couple of months ago my husband and I were toward the end of a long car trip and he decided to take a “short cut.” We were coming from the north, going south, and he somehow got us on some gravel roads in the boonies. When he turned onto one road, I wondered why he was going back north, but didn’t say anything. I figured he knew where he was going. When he realized he’d gone in a big circle and we were back on the road we’d been on just a few minutes before, he had a WTF?! moment. I said I wondered why we were going north. He gets confused when it comes to directions sometimes and hadn’t realized it. Do you think he blamed me for his mistake? Hell no. He just said “Whoops!” and we had a good laugh about it. Shit happens. We got over it. Certainly nothing to argue or end a relationship over, is it? Have relationships degenerated to the point that we’d rather get angry at someone else for not realizing you didn’t know what you were doing than accept the fact that it was your mistake and no big deal?
Alright, I was being a bit over-the-top when I said that “apparently everyone’s for themselves.” but it’s sort of the tone I’m generally hearing here, and yes, it does bother me. I’m willing to admit my mistakes, but my problem is that everyone is saying things like “oh, so she’s supposed to watch your every little move?”, which I feel is taking things out of context, and making me sound aggressive about passing blame. My point is that she noticed these things and didn’t speak, which is what I thought a friend should do. But okay, I was wrong about it. I had unreasonable expectations. I was out of line for getting upset.
(Snip)
How do you know this for sure tho’?
Bingo. I stay quiet while my SO passes our exit and stuff like that because I’m tired of being snapped at. In general I avoid anything that could remotely be considered criticism. Makes things much easier on me.
She told me.
You asked, people answered. You don’t like it, and I dig that. However, if you’re going to ask something like this, you have to be willing to accept that people may or may not agree with you. From what I’m reading here and from the tone you’re conveying, you don’t accept it all that well.
As a matter of fact, it sounds more like you’re suffering from a case of “But it’s all about me!!!”.
Just my view point. YMMV, of course.
It’s nothing major in it’s self. I would see if she’s one of those women, that don’t correct you, because their saving it up for the future. Everytime you disagree, all the little things she let pass will be brought up. Make sure it’s not a situation like that and then forget about it, lifes too short to be petty.
I probably would have pointed those things out in those situations. And it a whole lot of other situations. And my SO probably complains that I am a nag.
I guess it sorta seems like a slippery slope to me. If she starts pointing out things like the ones you mentioned, there’s a good chance that she’ll become the annoying person that I am who points out everything, even tiny little things that don’t make a difference one way or the other. (Why did you put your keys here? They belong there. Or why did you buy that brand? Usually we get this brand. Or you sliced the bread wrong. It should be done this way… all variants on things I’ve really said. I should try to be more like your SO and not correct every thing my SO does. ::sigh:
So yeah, maybe she should have pointed those things out (says the constant nagger) but if you ask her to, are you ready for her to point out everything you do that she disagrees with?
Oh yes. When we get in the car and my SO hands me the directions and tells me “Make sure I take the right exit” then I am alert and pay attention.
But I have faith in him. I trust him to get me to the right place. So if it’s not agreed I am to navigate, I often just zone out.
Well, then, if you’re certain she noticed but said nothing, I can more see your side of it.
Of course, she could be afraid to be snapped at, as others have suggested, or figured she must be missing something, or something like that. You’d have to ask her to point out those things, and agree that if you knew what you were doing, and you snap at her for pointing out what you already new, she gets to kick you in the face.
Well, what does she say when you say this to her?
Wait a minute. How exactly did the dialog go between you?
She actually told you “I knew you were f’n up but I let you anyway.”
On point 1, I agree that you’re making too big a deal of it.
On point 2, I’d be kind of annoyed myself. But not terribly so. Especially if I can use the ticket some other time.