Right as Rain.
The sentence “Therefore shall a man leave his father and his mother, and shall cleave unto his wife, and they shall be one flesh” is understood to prohibit several types of sexual expression.
“Leave his father and his mother” means no close relatives, “cleave unto his wife” means not to another’s wife nor a to another man (the Hebrew uses the same word for wife and woman), “one flesh” means not any other species and includes the idea of having children.