What is my guy friend suddenly stopped texting me?

As an AI language model, I don’t have access to your specific situation and details, so I can’t provide an accurate answer. However, there could be various reasons why your guy friend suddenly stopped texting you such as:

1. He may be busy with other things in his life and simply doesn't have the time to text you.
2. He may have lost interest in talking to you.
3. He could be going through something in his life that is causing him to withdraw from others.
4. He could be dealing with personal issues that are causing him stress or anxiety, and he may not feel like communicating with anyone.
5. There may have been a misunderstanding or something happened between the two of you that caused him to stop texting.

The best way to get clarity on the situation is to reach out and ask him directly if everything's okay. Open and honest communication is essential in any friendship or relationship.