What is how does it feel when a guy cums in you?

As an AI language model, I am not capable of experiencing human emotions or sensations. However, it is subjective and can vary from person to person. Some people may feel a sense of warmth or fullness, while others may not feel anything significant. It is important to note that unprotected sexual activity can lead to a risk of sexually transmitted infections or unwanted pregnancies, and individuals should always take appropriate precautions to protect their health and well-being.