If I search for someone on Facebook but don’t hit “add as friend” will they know I looked for them?

[Adamsman]

Some background of why I needed to know.
My uncle (my aunt's husband) has a much younger half-sibling who was 5 when his Dad died and my uncle wants to look him up on Facebook but not seek him out right away because the step-mother has been estranged from my aunt's in-laws (this uncle's family) since his father's death. He is not sure what the half-brother may know or not know but he heard the boy, now in his early 20's, had some issues with not having much extended family and no father so he thought of making an outreach. A family friend knows the step-mother's mother and that's how my uncle heard what the half-brother was going through. He told me to show him how to look him up where the half-brother wouldn't see right away until after the uncle's mother dies (she is terminally ill) and then he doesn't mind reaching out to the step-mother for the sake of the half-brother.

So is Facebook a safe site for this or will the person see people with this last name have looked for him. Its an unusual last name and so he would know it was family.
Also my uncle wants to know what other websites would not show his name as he knows mylife.com shows who has been looking and I told him Classmates shows.

[Daniel]

No

[Pilikika]

No they can't see that he looked them up

[loveday]

No because you are not adding them so why do they have to know if your creeping them face book is not that smart yet

[Daniel]

No They Wont There is no Way For anybody to Find Out Who Looked up Who Without Sending a Friend Request or Sending a Message or Anything