If I was in serious doubt I would have my kids babysat during day / overnight by trusted friend. Hire a wee car different make and colour from mine ( cash) and then follow him as he left the office at a discreet distance. Wear a wig and baseball cap. Re the Blackberry she can use it to phone her home number when he leaves it unattended then 1471 the house phone, then to cover tracks ask friend to phone straight after that. OR the bill for charges has the number on it, for o2 anyway! Mr Sense has one. If you are going to these lengths tho' you know all is not well in Paradise. I would also check out the home computer to see what has been done on it ... I have a techie I consult on these matters when the kids are being naughty ( son found his porn stash was made into slideshow screensaver , I can still see his face as the panic set in! lmfao.) Did you know that in some software programmes you can hide files ... perhaps someone will be able to impart the necessary steps for you to help her do that. Then she needs to clear history afterwards or he can see what she has been doing! Mr Sense thinks I used to be in the French Resistance. lol.