Crowley never got married. As said in book 8:
Crowley shook his head: "Married to the job, Halt. And never found the right woman." In truth, Crowley had long harbored a deeply felt admiration for Lady Pauline. But, being one of the few people in the Kingdom who knew how things stood between her and Halt, he had never let the fact to be known.
Kinda true, yes, but... can you imagine Crowley has never been in love with a woman? I honestly can't. I believe, that somewhere in his life, Crowley has been in love with someone. Just an ordinary woman, nothing special, except for Crowley. But before he got the change to tell her, or to let her know, she died. She died, in a fire, in a little village in Araluen fief. Crowley was the Ranger of Araluen fief and had not been able to prevent this. He came over it, but never fell in love again.