Yes, it's very common for guys to become interested in a girl who shows interest in them. Like anyone else, guys appreciate being wanted and valued, and when someone expresses genuine interest and attention, it can be flattering and appealing. This initial interest can spark curiosity and lead to the guy developing feelings or becoming more interested in getting to know the girl better.
Of course, individual reactions vary, and not every guy will automatically reciprocate interest just because someone shows interest in them. Some may not feel the same way or may not be ready for a romantic relationship at that moment. Additionally, it's essential to remember that each person is unique, and factors such as personality, values, and compatibility all play a role in forming a connection.
Ultimately, expressing interest in someone can be a positive and brave step, and it often creates opportunities for deeper connections to develop. However, it's essential to approach such situations with an open mind and respect the other person's feelings and boundaries. Communication and mutual understanding are crucial for building any successful relationship.