<human>: Can you provide a brief rundown of the text in within 3 sentences?

My gf and I have been together 5 years. She brought up marriage about a year ago, but I told her I was not ready and she said that she was ok with waiting several years. However, the other day I borrowed her laptop and went thorough her history. I know, I shouldn't have, but I was curious. And I've seen that she's been looking at wedding dresses for a while now.

I feel lied to and betrayed. Why would she tell me she is ok with waiting if she is doing this behind my back? I want to confront her, but I don't know how. Help me, reddit.
<bot>: GF and I decided to wait for a while to get married, I find out she is looking at wedding dresses online.