Yes, sorry, not trying to make you paranoid but GPS tracking can be put on your phone too.
Not sure how tech savvy he is, hopefully not very.
Also, one other thing (again, not trying to make you paranoid) as others mentioned, use incognito windows but if you haven't been and you clear history, you will need to clear cookies too (very annoying as this may wipe out some logins that you have saved for some websites) and temp files, deleting the history is not enough.
I hope you have your own computer and that it is password protected, that will make your life a lot easier.