Hence, we had 2 totally different vacation styles and in the end they were very hurt and my parents took their side. Since then, my cousin who I should add was very close with me.....has basically had nothing to do with me.
If it were me, this is where the hurt would be focused - the fact that you'd done nothing wrong (vacationed according to your style, assumed they were happy vacationing in their style), but your parents "took their side" when your cousin was offended. I'd be pretty irked if I felt my parents were encouraging your cousin's attitude, since this is basically a clash of styles rather than you doing something wrong to your cousin. Your cousin is taking offense at nothing, IMHO, but OTOH there's nothing you can do about that.
Anyway, my cousin has no problem leaving her kids with my mom and has often said to me...wow you could go away and leave your kids with your mom and you don't thats crazy! Little does she know the reason either!
I'm guessing this is less about your cousin not "knowing" how your mom is, and more a style difference, too. I would never leave my kids with my MIL back in the day, while most of our in-laws on that side made a regular practice of it. It isn't that they didn't see what I saw; it's that what bothered me didn't bother them.
My mom is overly involved with my life, or at least she tries to be, she has that type of personality, has to know everything even if it has nothing to do with her. I am more of a private person and I know she hates that. My cousin is very open with her and my mother eats that up.
All the way through your post, this is what I'm hearing - that you know your mom and your cousin have personalities that mesh better than your personality and your mom's. Yes?
Has anyone had a similar situation? Should I say something? Should I keep my mouth shut?
I have a similar situation, but it's my mom and my sister rather than my mom and a cousin. My mom isn't like your mom in wanting that kind of "enmeshed relationship," but my mom and my sister have much more similar personalities and are in some ways way closer and are definitely more comfortable with each other. Which means, alas, that mom is much more likely to take my sister's side in things. Although she's been known to have these great revelations where she calls me up, "Did you know your sister does x, y, and z?" and I'll be going, "Yeah, mom; where've you been all her life?"

But she forgets these issues almost immediately and then is again shocked when my sister is... my sister.
If you've already discussed the vacation where your cousin got offended and your mom shot you down with "you should have done what they wanted" or whatever, then I wouldn't bring it up again. From what you've said here, it sounds like your mom expects a kind of relationship out of you that isn't healthy, and if that's the case, she's not going to "get" that you honestly haven't done anything wrong, or that your cousin honestly has no grounds for the way she's acting. If your cousin has a similar personality, then they're both going to think you should have acted totally differently and they're just not going to be able to get past that.
My cousin barely speaks to me....only at family holidays which are very uncomfortable, she still is upset about the disney trip! I have tried by calling, sending cards, inviting her to family functions, but you can definitely tell she is not recipricating. Therefore, I continue to be myself, and try not to let this get to me, but it does.
When an adult sulks like a child, that'll get to anybody, even if you're not the one they're mad at.

I would continue to invite her to family functions that're appropriate for her and otherwise let it lie, which it sounds you're already doing.
Last year my cousing went on a cruise and only invited my parents, who declined only because it was to short of notice. Is this strange or normal? Please help me! Thanks so much for reading this...I know I rambled on a lot!
Very normal, but not very healthy. Both your mom and your cousin seem to be "high need," to expect attention and closeness that most people can't or won't tolerate, and when two people like that find each other they can get very close, whether they have a close relationship family-wise or not. It does sound like your mom and your cousin have some serious boundary issues, where there's almost a sense that they don't know where they end and where the people they love begin. They want a closeness and a "unity of mind" that simply isn't possible between two people long term unless one of them becomes a reflection of the other.
It's not surprising you're somewhat jealous of that, but it sounds to me like you also know on some level that it isn't healthy in the long run. Those kind of relationships do look really wonderful from the outside, but they can get pretty stifling as well. There's probably good reason you keep a bit of distance from your mom. If she's someone who crosses boundaries and has gotten very close to your cousin, either your cousin will narrow her life to what your mom wants, or she'll pretend to, or she'll reach a point where she just isn't going to be what your mom wants and there'll be a huge fall out. None of those are good things.
But I wonder if your desire to challenge the situation is another example of crossing boundaries? I am sure you're right that your mom would feel threatened and hurt if you had a relationship that close with an aunt, but does that mean you should feel the same way? Your mom has unrealistic expectations about how you should act toward her and others, but perhaps you have some unrealistic expectations as well. If you maintain healthy boundaries with your mom, but she wants a relationship with unhealthy boundaries, basically she has two choices. First, she could recognize that she has some issues and find a way to work those through in a healthy fashion. OR second, she could find some one who shares similar unhealthy attitudes, and get her fix that way.
I'm pretty sure she's going for door number two.

Probably you're right that the relationship is crossing boundaries and causing trouble. But you're not the one in a position to fix that, y'know? The main problem is the relationship between your cousin and your mom. You're suffering fall out from that problem relationship, but you're not in it, if you see what I mean. You can do what you can to keep your relationships with both of them healthy, but you can't improve their relationship with each other. The problem is that your mom and cousin both have unhealthy needs that they're using the relationship to care for, and you can't fix that. You can help them and support them in healthy ways, but if they don't want to change or don't want your help that's their right.
All you can change is your own reaction to the situation. Posting it here and laying it out is a good first step for that - you need to get a little distance from what's going on and get some perspective. Not distance from your mom, hopefully, but enough distance from what's going on that you can remember you love your mom and she'll always be special to you, but that she's also human and you're an adult now, so sometimes you're the one who has to be "the grown up" even if she is "the mom."

She'll always be your mom and you'll always be her daughter, even if she ends up spending more time with your cousin than with you.
It sounds to me like you're doing a good job in a difficult situation. I hope it gets better soon.
