 common sexual outlets among adults. Sexual intercourse generally refers to penile penetration of the vagina. {{cite book}}: Check |url= value (help)Clint E. Bruess; Elizabeth Schroeder (2013). Sexuality Education Theory and Practice. Jones & Bartlett Publishers. p. 152. ISBN 978-1449649289. සම්ප්‍රවේශය December 5, 2014. In many cultures around the world, vaginal sex is what is usually implied when people refer to 'having sex' or 'sexual intercourse.' It is the most frequently studied behavior and is often the focus of sexuality education programming for youth.Cecie Starr; Beverly McMillan (2015). Human Biology. Cengage Learning. p. 339. ISBN 978-1305445949. සම්ප්‍රවේශය December 27, 2017. Coitus and copulation are both technical terms for sexual intercourse. The male sex act involves an erection, in which the limp penis stiffens and lengthens. It also involves ejaculation, the forceful expulsion of semen into the urethra and out from the penis. [...] During coitus, pelvic thrusts sti