It is true to say that sexual orientation change during puberty.
The main change is physical growth. There is also sexual growth as in reaching sexual maturity.
is the period during which adolescent reach sexual maturity
During puberty, hormone production increases. The hormone testosterone, produced in the testes beginning in puberty, is responsible for sex drive.
The cause of Puberty is the change in hormones in the childs body. Increases of Testosterone and estrogen bring sexual maturity.
During and after puberty, most girls will become sexual, though the degrees will vary per person.
Puberty.
adrenals
During puberty, the penis and testis increase in size. also , the libido of a person increases. Males start ejaculating and masturbating to achieve orgasm.
adrenals
adrenals
It is not likely unless something has penetrated the vagina such as a tampon before hand.
There is increase in libido. also onset of menstruation.