I asked my gf on break where she was and she lied to me. She was in the pub?!

I have a girlfriend of many years and we have a break now. We talk to eachother on daily basis. She had an revenge affair with some guy back in January but i forgave her and we became a couple again, but as I mentioned, were on a break at the moment.

Yesterday at midnight i tried to call her. She didn't answer the moment, But imidiately after she sent me an sms with the sentence "I can't answer the phone, my grandmother is here" (at her apartment). I Then tried to log in to her iCloud account as she uses the "Find-my-iPhone"-feature, and to my surprise I entered a correct pass which was a simple one. I then could se throguh gps that she wasn't at home at all, she was in the pub! I then confronted her saying that i knew she was in the pub and she started to suspect some gps hack. She first tried to say "no, i am really at home" but after a short while she admited that she was in the pub as I described the pub name. She said she was gone out because of diversion from kids and that she was sitting home most of the time. And she also admited that she was drinking. She then said she was sorry for lying and she was about to go home. I started to ignore her from that time by not sending many sms and answering her calls. After she sent last message about 0230AM when pub closed she used 1hr 40mins to go home which is 5mins walk away & turned off gps. She was propably stadning outside pub area talking to guys. She hasn't sent me message since then.

How should I deal with this?

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