One of these tissues by itself is called a corpus cavernosum.
A man can also become sexually aroused without being touched, for example, if he sees a naked person or thinks about having sex with someone.
It should be noted that tight elastration for an extended period can kill your nipple.
For heterosexual men, this is because it is thought that when the penis can go further into the vagina, this helps the woman have a better orgasm.
It is also common for a man to wake up after a night's sleep to find that he has an erection.
This can happen if he is touched sexually, or even if he is not touched — for example, if he sees a or thinks about having sex with someone else.