There are 2 things I don't understand at all with this situation. 1. He was too drunk to realize his texting was wrong, couldn't remember it the next day, BUT knew enough to tell the 'friend' you wouldn't be around Monday? Puleeeze. 2. IF, IF alcohol is solely to blame for his behaviour, and he never meant to hurt you, YTF is he STILL drinking??
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You mistrust him for valid reasons, don't set yourself up for hurt, dissapointment and diseases. There are plenty good men out there, don't settle.