A reproductive and sex organ that’s made of spongy tissue. The spongy tissue fills with blood during sexual excitement, a process known as erection (getting hard). Urine and semen pass through the penis.
From a heteronormative point of view, the first thing that comes to mind when the word sex is mentioned isn't foreplay or oral sex, rather, it's straight up penis penetrating a vagina. Limiting is an understatement.