'Commit Adultery' in the Bible

you who preach against stealing, do you steal? you who declaim against adultery, do you commit adultery? you who abhor idols, do you commit sacrilege?

loves others hath fulfilled the law. for this, "thou shalt not commit adultery, thou shalt not kill, thou shalt not steal, thou shalt not bear false witness, thou shalt not covet;" and whatever social precept there be, it is reduced to this single head,