DP of 4 years knows my passwords to online accounts and my phone. It's not like I sat him down and gave them to him, it's just never been a big deal, my social media and email accounts are always logged in on my laptop anyway.
I know his phone password. He was at work and I wanted to buy something using his Amazon prime subscription in order to get free next day delivery. I called and asked him for the password and he refused saying it was the same password for all his online accounts, email, bank etc. I joked that I wasn't planning on stealing money from his bank account and he said that the bank advises to never hand it out to anyone.... 
I wouldn't think twice about offering him my password for anything if he needed it. He said I could send him the details of the things I wanted to buy and he would get them for me via his account. I'm a bit pissed off now and have ordered them from my own account. What on earth does he think I'm going to do?