I just want to put this scenario out there to get opinions... there is a little more to this, but for now want to process this individual incident.
Yesterday morning DH asked me to hang out some washing he put in to make sure it was dry for the evening. This is slightly unusual as he would normally leave it until the last minute to find something clean to wear. That evening he went to watch the footy at a local pub. He took £20 quid with him. At midnight I checked find my iPhone to see if he was on his way home, he'd switched it off from his phone. I woke at 8am to no sign of DH and worried children. Called him, phone off. Last seen on WhatsApp at 1am. Tried again an hour later, rang, but no answer. Checked find my iPhone and could see he was about 4 miles away, looked to be walking home from the nearest town. He called me back and said he'd been at a party and fell asleep. I took the (now reassured) DC out for the day, DH got home and went to work.
The little more (realising I don't want to dripfeed) is that he has a history of addiction. Also, our relationship is not good at the moment, hasn't been for a few months. He has threatened (during heated arguements) that he will go elsewhere.
He's fast asleep, just tried to peek at his phone and he's changed the passcode (first time in 10 years).
He knows I check find my iPhone occasionally and doesn't like it, sees it as an invasion of privacy - he will likely justify the secrecy as protection of this...