It can be challenging to determine someone's sexual orientation based solely on their behavior. Pranks and jokes can often be misleading and misinterpreted, so it's important not to jump to conclusions. Instead of trying to guess or assume, it would be more productive to have an open and honest conversation with this boy.

- Start by finding an appropriate time and setting to talk to him privately.
- Express your feelings calmly and honestly. Let him know that his pranks and mixed signals have caused confusion and hurt.
- Give him the opportunity to explain his actions and intentions. Ask him directly if he is gay or not, but remember that it is ultimately his choice whether or not he wishes to disclose his sexual orientation.
- Respect his response, whatever it may be. It's important to understand that sexual orientation is personal, and everyone has the right to their own journey and self-discovery.
- Depending on his answer and how he handles the conversation, you can decide whether you still want to pursue a relationship with him or if it's best to move on.

Remember, communication is key in any relationship. Openly discussing your feelings and concerns can help bring clarity and understanding.