I had sex with my friends girlfriend

my friends deeply in love with this hot girl ( u shuld see her ass!) but i recently started hanging out with her.. u know, movies, lunch and shit and  out of nowhere she offered me sex which i gladly took. ever since, ive been fucking her on the side when the dude's not around. getting head n shit from her doing everything i can think off. my pal was suspicious and asked me if i thot his gal was cheating on her. i told him to ease back n stop being paranoid. im in the process of trying to organise a 3-some with one of her friends. i feel no guilt!