Marek

“Jon, did you ever wonder why the men of the Night's Watch take no wives and father no children?'' Maester Aemon asked.

Jon shrugged. ''No.'' He scattered more meat. The fingers of his left hand were slimy with blood and his right throbbed from the weight of the bucket. ''So they will not love'' the old man answered ''for love is the bane of honor, the death of duty”
― George R.R. Martin, A Game of Thrones