Past few days I have using a bit of dirty pillow or gap between sofas for masturbation without using any protection like condoms because I can't keep it anywhere as I am a student and live with my parents, those areas where not that much dirty also after the masturbation session I used to clean my penis with water of outer side because the upper part of penis is tight and doesn't stretch very well but I used to clean it properly but I am a bit worried that if there is any chance that it can cause me sexual diseases and infection so can you tell me what can happen or what are the chances of worse? What precautions should I take to ensure a healthy practice?