(someone) not only (did something), (they)(did something else)

You've probably learned to use "not only ___ but also ___". It's used when:

• You think something is very good, very bad, very easy/difficult/big/small/interesting/boring/etc.
• There's also another thing, which is also good/bad/easy/difficult/etc.
• When you add the 2nd thing to the 1st thing, it's unbelievable.

In real English conversation and writing, people don't always include "but also". Sometimes they use "too":

I not only fixed it, I cleaned it up too.

Or you can use "even":

She not only didn't show up, she didn't even call or send a text.

Or you can just say the 2nd thing without any connecting words, like in the example at the top.

disobey (someone)

This means to do something that your parents, teacher, or boss told you not to do. This phrase wouldn't be appropriate to use to describe something your friend, husband or wife, or parent did. You can only "disobey" someone if they have complete authority over you.

betray (someone's) trust

When someone trusts you, and you do something to hurt them, you have betrayed that person's trust. This phrase describes a very strong feeling, only used for very bad situations like this one:

Sandra Bullock's husband betrayed her trust by cheating on her with another woman.