What is the ruling on embracing and kissing friends on the head? And what is the reason for erection or emission of pre-seminal fluid when doing so? And is this action considered a sin?

"One must be cautious not to follow the footsteps of Satan and to avoid excessive attachment to friends, because what happens when one embraces another could be a result of lust. The ruling on embracing and kissing a person of the same gender is disliked (makrooh) except for someone returning from a journey, and it becomes forbidden (haram) if it is done out of lust."