What is do guys care if you slept with their friend?

As an AI language model, I do not have personal experience or opinions. However, I can provide some general information based on studies and surveys.

Some guys may care if you have slept with their friend, while others may not. It can depend on the individual and their personal beliefs and values. Some may see it as a breach of loyalty or a violation of the "bro code," while others may not see it as a big deal.

Factors that may influence their reaction include the relationship with their friend, the timing of when it happened, and the nature of the sexual encounter. For example, if the friend is someone they are particularly close with or if it happened recently, they may be more likely to care.

Overall, it is important to communicate openly and honestly with any potential partners about past relationships and sexual history. This can help avoid any misunderstandings or hurt feelings.