Dear Welcome to HCM We understand your concerns I went through your description. I suggest you not to worry too much. Urethral opening is like your anus opening. It is very much elastic and can become larger according to the requirement. When your urine is delayed and when the body needs to pass it fast, the orifice get bigger and allows larger quantity of urine. When masturbating, due to the forward and back movement applied on the penis, the elasticity of the urethra opening increases and it looks larger. This happens with everyone and there is nothing to worry or get alarmed. You might need psychological counseling., I am more than happy to provide telephone psychological counseling through healthcaremagic. Contact me through customer care, www.healthcaremagic.com. Hope this answers your question. Available for further clarifications. Good luck.