Don't confuse guilt with embarrassment.
What's so embarrassing about it? Embarrassing is when you slip and fall. That's something you have no control over. Embarrassing is getting in front of a crowd of people with your fly unzipped. Again, not something you can control. We are talking about a conscious act that is knowingly performed. I wouldn't call that embarrassment, I would call that shame (a painful emotion caused by consciousness of
guilt, shortcoming, or impropriety; Merriam-Webster dictionary). I unknowingly discovered masturbation when I was 10. It's not something anyone ever talked to me about so I don't think it was an embarrassing thing. It was something that I felt I should conceal and I felt that way naturally. Why would this act need to be concealed?
From just a religious standpoint then it is certainly immoral. Masturbation is a result of lustful thoughts. Isn't lust a deadly sin? In the Bible read Ephesians 5:3 "But fornication, and all
uncleanness, or
covetousness, let it not be once named among you, as becomes saints" This verse doesn't name masturbation specifically but it would definitely fall into that category. Furthermore in Romans 14:23 it says "And he that doubteth is damned if he eat, because he eateth not of faith:
for whatsoever is not of faith is sin." In other words if the act is not giving glory to G-d, then what is the point of it? Is masturbation something you feel embarrassed about before G-d? So tell me what is so G-dly about masturbating? Here, the Bible calls it sin. Also look at 1 Corinthians 6:19-20 "What? know ye not that your body is the temple of the Holy Ghost which is in you, which ye have of God, and ye are not your own? For ye are bought with a price: therefore glorify God in your body, and in your spirit, which are God's." Here the reader is told that his body is not his own, but G-d's and it should be glorified.
In the Qur'an 23:5-7 "And those who guard their chastity (i.e. private parts, from illegal sexual acts). Except from their wives or (the captives and slaves) that their right hands possess, - for them, they are free from blame. But whoever seeks beyond that, then those are the transgressors." Masturbation would be classified, here, as an illegal sexual act. Many Muslim scholars, however see it as permissible ONLY as a deterrent to adultery, and a last resort. Even so, there is a level of shame/guilt associated with it under the most extreme circumstances.
If you are embarrassed or ashamed about an act, then that means there must be something wrong with it. And I'm not talking about me, I'm talking about
YOU! A good test for whether something is immoral or not is whether you would be proud to tell others what you had just done. Again, do what you know is right, avoid what you know is wrong, and if you have to question it, it's probably wrong too. You are trying to justify something you know to be immoral deep down inside. Of course the issue in this thread is nude pictures. Yes looking at nude pictures is immoral. If someone walked in on you looking at some pornography what would you do? (hint the answer is in the answer)