How should I confess that my girlfriend?

I was with my best friend for a visit and had been all day so hot .. I was a moment .. I .. I started playing around with my pussy .. until I was alone suddenly disturbed by a friend of my girlfriend. I, had already fallen into ecstasy, I noticed not at all, he jerked his cock next to me .. he took advantage of the situation and pushed my dick in my mouth !! and not just in there .. How should I confess my girlfriend the only ??