yes its Normal and common, jesy males kay penis meah erection say penis meah hardness or size meah change aati hay bilkol essi turha females meah vagina walls or outer and inner lips meah bhe blood flow or contractions say change ata hy or clitoris bhe size meah bura ho jata hay or erect ho jata hay jesy penis or libia majora or limbia minora blood kay pressure say swell up jaty ess leyeh vaginal contractions say outer vagina size change hota hay eski waja say onko esaa feel hota hay dont worry its normal all changes which she observe during sexual excitement,