Yesterday my Gf that i live with lost my keys when at a café. (The keys have been found again this morning, but she is still angry at me for getting upset that they were lost to begin with.)

She tells me that she was afraid to tell me they were lost to begin with, because she knew i would get upset. 

For me, it's not as much that she lost the keys but the fact that she told me that "These things happen" and i "shouldn't get upset over it."

The keys were also not only for my apartment, but for my parents, our only mailbox key as well as our bike keys.

I told her that it was a trust thing. I gave her something of mine and she lost it. She defends herself by saying that it wasn't as if she tried to lose them, it was an accident. She also says that it's not as if she was cheating so i shouldn't be this upset.

Her grandparents are here as well, and she says that they too noticed i was angry today.

This also happened right after i had to return the phone i bought her for BD present 6 months ago because of water damage.

Who's in the wrong here? Am i over reacting? 

From her perspective, i shouldn't be angry at her because it was an accident.

From my perspective, she lost something of mine and i felt that she didn't take it seriously.

I'm an insanely pragmatic person, and i try to always take full responsibility for everything bad that happens to me, and i wish she would take responsibility for this instead of trying to make it my fault for being upset.

I tried talking to her, and right now she is outside crying, so...yeah...
user
GF lost my keys and i got upset. She justified it by saying that it was an accident and that i shouldn't be upset.
assistant
Yesterday my Gf that i live with lost my keys when at a café. (The keys have been found again this morning, but she is still angry at me for getting upset that they were lost to begin with.)

She tells me that she was afraid to tell me they were lost to begin with, because she knew i would get upset. 

For me, it's not as much that she lost the keys but the fact that she told me that "These things happen" and i "shouldn't get upset over it."

The keys were also not only for my apartment, but for my parents, our only mailbox key as well as our bike keys.

I told her that it was a trust thing. I gave her something of mine and she lost it. She defends herself by saying that it wasn't as if she tried to lose them, it was an accident. She also says that it's not as if she was cheating so i shouldn't be this upset.

Her grandparents are here as well, and she says that they too noticed i was angry today.

This also happened right after i had to return the phone i bought her for BD present 6 months ago because of water damage.

Who's in the wrong here? Am i over reacting? 

From her perspective, i shouldn't be angry at her because it was an accident.

From my perspective, she lost something of mine and i felt that she didn't take it seriously.

I'm an insanely pragmatic person, and i try to always take full responsibility for everything bad that happens to me, and i wish she would take responsibility for this instead of trying to make it my fault for being upset.

I tried talking to her, and right now she is outside crying, so...yeah...
user
GF lost keys and said it was an accident. I got upset, she defended herself by saying she didn't lose them. She also said that i shouldn't be this upset over it. I tried to talk to
assistant