A Brisbane woman stabbed a male friend twice in the shower after he refused to stop masturbating in front of her children.

Defence lawyers for Kylie Louise Wilson, 28, said the mother of two "lost it" when her friend of six years, Daniel Peter Blair, went on a masturbation marathon on April 6 last year.

Brisbane's District Court this morning heard Mr Blair had showed up at Wilson's Birkdale unit, in Redland Shire, where he took amphetamines before having a shower.