Although many erect penises point upwards (see illustration), it is common and normal for erect penis to curve in any direction. Many penises are curved in right, left, upwards or downwards direction depending upon the tension of the suspensory ligament that holds it in position. Psychology of Men & Masculinity: “Does Size Matter? Men’s and Women’s Views on Penis Size Across the Lifespan.4"

Like your upward counterpart, your curve also gives you an edge when it comes to reaching the hot spots that run along the front wall of the vagina or rectum. a b Burch, R. L.; Gallup, G. G.; Mitchell, T. J. (2006). "Semen displacement as a sperm competition strategy: Multiple mating, self-semen displacement, and timing of in-pair copulations". Human Nature. 17 (3): 253–264. doi: 10.1007/s12110-006-1008-9. PMID 26181472. S2CID 31703430. Schultz, W. W.; van Andel, P.; Sabelis, I.; Mooyaart, E. (December 18, 1999). "Magnetic resonance imaging of male and female genitals during coitus and female sexual arousal". BMJ. 319 (7225): 1596–600. doi: 10.1136/bmj.319.7225.1596. PMC 28302. PMID 10600954. An erection is the stiffening and rising of the penis, which occurs during sexual arousal, though it can also happen in non-sexual situations. Spontaneous erections frequently occur during adolescence due to friction with clothing, a full bladder or large intestine, hormone fluctuations, nervousness, and undressing in a nonsexual situation. It is also normal for erections to occur during sleep and upon waking. (See nocturnal penile tumescence.) The primary physiological mechanism that brings about erection is the autonomic dilation of arteries supplying blood to the penis, which allows more blood to fill the three spongy erectile tissue chambers in the penis, causing it to lengthen and stiffen. The now-engorged erectile tissue presses against and constricts the veins that carry blood away from the penis. More blood enters than leaves the penis until an equilibrium is reached where an equal volume of blood flows into the dilated arteries and out of the constricted veins; a constant erectile size is achieved at this equilibrium. The scrotum will usually tighten during erection.Penis panic ( koro in Malaysian/ Indonesian) — delusion of shrinkage of the penis and retraction into the body. This appears to be culturally conditioned and largely limited to Ghana, Sudan, China, Japan, Southeast Asia, and West Africa. Like the penis, sperm competition has caused the human testicles to evolve in size through sexual selection. [35] This means that large testicles are an example of a sexually selected adaptation. The human testicles are moderately sized when compared to other animals such as gorillas and chimpanzees, placing somewhere midway. [41] Large testicles are advantageous in sperm competition due to their ability to produce a bigger ejaculation. [42] Research has shown that a positive correlation exists between the number of sperm ejaculated and testis size. [42] Larger testes have also been shown to predict higher sperm quality, including a larger number of motile sperm and higher sperm motility. [35] How to stop an unwanted erection: 7 remedies". Medical News Today. 2018-01-04 . Retrieved 2021-10-22. Main article: Circumcision A labelled dorsal view of a circumcised penis: (1) shaft; (2) circumcision scar; (3) corona; (4) glans; and (5) meatus

Pro tip: If you’re going au naturel, be sure to keep things clean and fresh. If you or a partner prefers a trim or hairless nether region, take care to avoid painful mishaps. SmoothSarah Attwood (15 May 2008). Making Sense of Sex: A Forthright Guide to Puberty, Sex and Relationships for People with Asperger's Syndrome. Jessica Kingsley Publishers. p.62. ISBN 978-1-84642-797-8 . Retrieved 22 July 2013.

Before you begin measuring, your penis should be erect, and you should have a measuring tape, a ruler, or a piece of string at hand. Masters, W. H.; Johnson, V. E. (1966). Human Sexual Response. Boston: Little, Brown and Company. ISBN 9780316549875. With no angles to accommodate, you can eenie-meenie-miney-mo your way through every sex position you both consent to with little-to-no tweaking required. Ruth Bell, Changing Bodies, Changing Lives: Expanded Third Edition: A Book for Teens on Sex and Relationships, ISBN 0307794067, p. 15a b "The Stallion: Breeding Soundness Examination & Reproductive Anatomy". University of Wisconsin-Madison. Archived from the original on 2007-07-16 . Retrieved 7 July 2007. A thrombosis can occur during periods of frequent and prolonged sexual activity, especially fellatio. It is usually harmless and self-corrects within a few weeks. Genetics is the most important predictor of your penis size. Just as your eye and skin color are determined by your hereditary factors, so is your penis size. Studies have found another factor to be a strong indicator of flaccid penis size — height. Not surprisingly, your height is also determined by your genetics.