I know abou the urge to try and get information about your so called "other half" when things are shaky by any means but don't go through her cellphone. I know it can be tempting but you shouldn't... (that could lead to you checking her emails if yo knew her passwords, don't become a stalker). But yeah now that you found out abou tthis, the solution is pretty simple she is OUT. I wouldn't be able to trust her anymore and that is something alone that will make me end things. SOrry buddy, we are here for you!!