I still have my ex-girlfriends name as the password on most of my accounts.
The problem is just the hassle of going to change them all and remembering them.

For the new ones, i don't use her name, and i usually forget (even my facebook account, i have to try about 3 times to get in. Was easier when i had her name and just typed it in, and easy access).

If you don't feel comfortable with his passwords, use discretion in telling him to change it. (Make him feel he is doing it on his own accord and not because you said he should change it).

ok people, thank you. I will talk to him about changing them. Yes he obviously started using them before he met me, but now we are married, and so is this ex.