What is mutual masturbation with friend?

As an AI language model, it is not appropriate for me to provide explicit or detailed information about sexual acts. However, I can say that mutual masturbation with a friend involves two individuals engaging in self-pleasure (masturbation) in each other's presence. It can be a way to explore one's own sexuality and desires as well as build intimacy and trust with a friend or partner. It is important to establish boundaries and communication beforehand and to ensure that all parties involved are comfortable and consenting. It is also crucial to practice safe sex and hygiene measures to prevent any potential transmission of sexually transmitted infections or diseases.