Boyfriends may chat with other girls for many reasons. Here are some possible explanations:

1.*** Same interests: If a boy and a girl have the same interests or topics, they may have a good chat. This does not necessarily mean that they have an improper relationship, but they may have something in common on a topic.

2. Friendship: Boys and some girls may be just ordinary friends, and the chat between them may be just daily communication.

3. Opposite-sex communication: Some boys may enjoy the feeling of interacting with the opposite sex more, which may be because they have few opportunities to interact with the opposite sex in the same-sex social communication. However, this does not mean that they have an improper relationship with these girls.

4. Lack of sense of boundaries: Sometimes, even if there is no proper relationship, boys may still chat with other girls because of lack of sense of boundaries. This may be because they don't know how to deal with this situation properly, or because they don't think this behavior will bring problems to their relationship.

5. Attraction: Some boys may be attracted to girls with certain characteristics, such as intelligence, fun, kindness, caring and so on. So, they may have a good chat with these girls, but that doesn't mean they want to establish a deeper relationship with them.

In short, there may be many reasons for boyfriends to talk to other girls. If you feel uneasy or uncomfortable, you should communicate directly with your boyfriend and ask him what he thinks and feels. By establishing better communication, you can better understand each other's thoughts and feelings and handle this situation better.