A man looked at me with a bad smile.

If a boy looks at you with a bad smile, it may mean that he thinks you are interesting, or he may have some special feelings for you. However, this behavior itself does not necessarily represent any particular emotion or intention.

If you are curious about this boy's intentions, you can try to talk to him and ask him what he thinks. If you don't want to communicate with him, you can also ignore his behavior or respond to him in the same way to show that you don't like this kind of interaction.

No matter which way you choose, remember not to interpret others' behaviors or intentions too much, which may lead to misunderstanding and unnecessary anxiety. The most important thing is to maintain self-confidence and self-awareness to cope with any situation.