What happened:

So me and this girl have really been hitting it off, in two weeks I've slept over at her place 6 times just hanging out and hooking up. On the sixth night we have sex, we really like each other.

Then I go home for 5 days, I come back and shes all "lovey dovey", we talk about how now she's my girlfriend, and maybe 2 hours later she makes a joke about how all these weird guys message her on facebook:

I go to look, and I see that this guy messaged her flirting with her and SHE GAVE HIM HER NUMBER. He then texted her, and she claims she never responded, but deleted the text. This is after we had sex, while I was away, and while we were very much into each other.

I spend the next 30 minutes putting my clothes on trying to make sense of if I should be mad, why she would do that, while she essentially says that "I was bored, it was a mistake, I really like you".

I ended up not leaving, because I have never felt so strongly about someone after such a short period of time... or ever really, and because I truly know that she really really does like me, and because I could see that If I was bored and technically didn't have a girlfriend, maybe I'd give a girl my number that was hitting on me. 

The BIG PROBLEM:
Now, even if I brush off what happened and just take it as "we weren't technically dating,"  how do I go back to seeing her the same way I saw her before? Everything we had was so innocent and fun, and now I feel like it's completely ruined. I don't look at her with love in my eyes now. I look at her and just feel sad.

When she picked me up the night of, I would sit in the passenger seat smiling, looking at her, making jokes so that she would smile. When I rode back the next morning I just didn't feel comfortable, I couldn't look at her. I felt ashamed in a way... I don't know what to do. I would really appreciate any advice
user
GF gave guy her number before we technically dated, now I can't look at her in the same way I did before, need
assistant
What happened:

So me and this girl have really been hitting it off, in two weeks I've slept over at her place 6 times just hanging out and hooking up. On the sixth night we have sex, we really like each other.

Then I go home for 5 days, I come back and shes all "lovey dovey", we talk about how now she's my girlfriend, and maybe 2 hours later she makes a joke about how all these weird guys message her on facebook:

I go to look, and I see that this guy messaged her flirting with her and SHE GAVE HIM HER NUMBER. He then texted her, and she claims she never responded, but deleted the text. This is after we had sex, while I was away, and while we were very much into each other.

I spend the next 30 minutes putting my clothes on trying to make sense of if I should be mad, why she would do that, while she essentially says that "I was bored, it was a mistake, I really like you".

I ended up not leaving, because I have never felt so strongly about someone after such a short period of time... or ever really, and because I truly know that she really really does like me, and because I could see that If I was bored and technically didn't have a girlfriend, maybe I'd give a girl my number that was hitting on me. 

The BIG PROBLEM:
Now, even if I brush off what happened and just take it as "we weren't technically dating,"  how do I go back to seeing her the same way I saw her before? Everything we had was so innocent and fun, and now I feel like it's completely ruined. I don't look at her with love in my eyes now. I look at her and just feel sad.

When she picked me up the night of, I would sit in the passenger seat smiling, looking at her, making jokes so that she would smile. When I rode back the next morning I just didn't feel comfortable, I couldn't look at her. I felt ashamed in a way... I don't know what to do. I would really appreciate any advice
user
Caught girl who I was falling very hard for sending her number to a random FB guy before we technically started dating. Now
assistant