The activity of two persons use their reproductive parts.
If one of them lost, it's a rape.
If both of them are happy, it's a pleasure.
If it's the first time, it's awkward.
If both of them want more, it's addicted.
It is a act that two or more people have it is how you make babies first you enter the penis in the vagina and sperm produces and sometimes it ends up with a baby.