Contacts linked

Hello. I have a question. In my boyfriends phone, my contact name was linked in his phone to his email account and iCloud email. He thinks I did this for some reason. How could this happen and what benefits would this have for me? In my phone, I have him linked to his shop phone as well as his own email but he’s saying I was linked to his personal stuff and feels I did this to gain access to things on his phone. Is this possible?