What causes a female squirting orgasm?

Not well understood.: “squirting” is controversial. Some indicate that it is a form of female ejaculation in which the fluid is propelled from para-urethral ducts during or prior to orgasm. Others hold that it is lubricating secretions or incontinence of urine.

Still being studied: Female ejaculation is the expulsion of fluid by the paraurethral ducts through and around the human female urethra during or before an orgasm. It is also known in slang as gushing or squirting. Some women, if stimulated in the right area, can "squirt" during or as part of an orgasm. Women can still orgasm without squirting too. Hope this helps.