<human>: Provide a brief overview of the text.

Alright, this all sounds so childish when I type it out.

I was texting an ex (the one I was seeing before my current gf) that was coming through town and grabbed a beer with her. I tried to cover up because I didn't want my girlfriend to get upset, I had no intentions of anything happening, really, I just wanted to wish my ex well so I didn't see the harm. 

I changed the ex's name in my phone because she had been asking me for recommendations on nightlife and food and I was horrified my girlfriend would see the original name and get upset. 

Well after a 20 minute catch up I was on my way to my girlfriends. Of course she saw the texts and questioned me on it, at first I lied to her about who it was. Eventually just came clean. Broke up.

This is the second time I've lied to her, the first was a very similar situation at the start of our relationship. We met up yesterday to exchange stuff, says she still cares a lot for me but could never trust me after this second time. I really care about this girl, what do?
<bot>: Grabbed a beer and exchanged texts with an ex when they were passing through town. Lied about it to current GF. Now broken up and upset about how it went down. Advice?