Three days ago I discovered that dh was blackberry messenging an ex, someone who he had been obsessed with and going to marry prior to meeting me. She now apparently lives near us and remains unmarried (i have been married to dh for 8 yrs).
Everything on his phone is passcode protected but i managed to hack into the messenging app and read pages of messages between them, which were enlightening. He is apparently smoking weed, which I had a times suspected but he had vigorously denied. I am very anti-drugs.
I spoke to him about his messaging her, without revealing the extent of what I had read or explaining that I knew his passcode. He apologised and said he would not message her again. The following day I checked his phone and he was continuing to message her.
I asked him if he had messaged her, he said no, offered to delet app to reassure me. I asked him to show me, he got his phone and showed me there were no messages then deleted the app. So basically a complete lie to my face, no signs at all.
I explained I had checked his phone less than 10 minutes prior and there had been messages. He was pretty cross I had invaded his privacy 
Since then it has been an emotional rollercoaster for me. I feel sad one moment, angry the next and occassionally wish I could just forget the whole thing. I can't trust him anymore, he can clearly lie to me with great ease.
He has only given very roundabout apologies....."I am sorry for how this has made you feel" etc.
Am finding it really hard to cope, wondering what else has been lies over the years. 