When it comes to discussing masturbation with a 16-year-old friend, it's important to approach the topic with care, respect, and understanding. Masturbation is a natural and common behavior among teenagers exploring their bodies and sexuality.

Is it okay to teach your friend?
Yes, it is okay to share accurate and respectful information if your friend asks, as long as you both feel comfortable. However, it’s important to ensure that this conversation is private, consensual, and respectful of both your boundaries.

How to prepare him for ejaculation:
- Explain that ejaculation during masturbation is normal and is the release of semen from the penis.
- Let him know that it might feel unusual or surprising the first time, but it’s nothing to worry about.
- Suggest a comfortable and private setting where he won’t be disturbed.
- Encourage gentle touch and experimentation to understand his own body’s responses.
- Inform him that it’s normal for the amount of semen to vary and for the experience to differ each time.

How to clean up afterward:
- Advise keeping some tissue, a clean cloth, or paper towels nearby to clean up the semen after ejaculation.
- Suggest washing the hands and genital area with warm water and mild soap to maintain hygiene.
- Remind him to dispose of tissues or towels properly.
- Emphasize that maintaining cleanliness can help prevent irritation or infections.

Remember, if either of you feels unsure or uncomfortable, it’s okay to seek information from trusted adults, healthcare providers, or sexual health educators. Supportive, accurate education is key to healthy sexual development.