Is that any relation betwen acne and sex hormones (mastrubate , watch pornography ...)?

No: Physical activities that you listed do not inflame or activate acne --- however acne is related to hormonal changes that occur during adolescence.

Masturbation: You may be very surprised by the loud and accurate response your question is generating here. Physicians see so much damage done to teens and others when it comes to false myths around sexuality. I think that many of us feel that if we can help just one kid have a better understanding of their body then we have done our job for today. The honest and true answer is a loud NO.