To kiss or caress with your lips, even open your mouth, use your tonge and exchange saliva. Genetics: science dealing with hearditary, variation, reproduction, related to a gene; the biological factors determining heredity. The heredity tendency of an organism is to transmit its own nature to its descendants. So there is much to one open mouth kiss and even more to sexual exchange of bodily fluids. You are like all other 30 peoples " genes" for four generations back, even their zodiacal signs effect you.
