My dear friend, a man in love is not only foolish but dangerous.
 Guy de Maupassant, Bel-Ami (1885). copy citation

add
Author Guy de Maupassant
Source Bel-Ami
Topic love
Date 1885
Language English
Reference
Note
Weblink https://en.wikisource.org/wiki/Bel_Ami

Context

“she smiled indifferently and replied calmly: "Oh, you can come just the same; no one loves me long." "Why not?" "Because it is useless, and I tell them so at once. If you had confessed your fears to me sooner, I would have reassured you. My dear friend, a man in love is not only foolish but dangerous. I cease all intercourse with people who love me or pretend to; firstly, because they bore me, and secondly, because I look upon them with dread, as I would upon a mad dog. I know that your love is only a kind of appetite;” source