Option 1: Set the one that needs to scan the avatar or fingerprint, so that he can't play with your computer while you are away. When you come back, if he says he wants to borrow your computer, you say you also want to use it. If you have nothing to do, you can't say anything when he watches you study, can you?

If your computer can't set up:

Option 2: He calls you, but you don't answer, and then tell him that when you go to the study room or the library, your cell phone is silent and you don't hear it ~ ~ ~

Option 3:

After changing your password, he asked, you said that your password involved a lot, suggesting that he might be related to the bank card password or something. In a word, that password is very important and can't be told to others. Even if we trust each other again, it is impossible to tell others what the bank card password is. If he asks you to change your password, you will keep silent, so that he will have self-knowledge ~ ~ ~

PS: Keep a good attitude to study. Don't disturb the rhythm for some trivial things in life. I hope it works for you. Let's go