The Collaborative International Dictionary of English v.0.48:

Unaffectionate \Unaffectionate\
   See affectionate.

WordNet (r) 3.0 (2006):

unaffectionate
    adj 1: lacking affection or warm feeling; "an uncaring person"
           [syn: detached, unaffectionate, uncaring]

Moby Thesaurus II by Grady Ward, 1.0:

62 Moby Thesaurus words for "unaffectionate":
   affectless, anesthetized, arctic, autistic, blunt, catatonic,
   chill, chilly, cold, cold as charity, cold-blooded, coldhearted,
   cool, disagreeable, dispassionate, drugged, dull, emotionally dead,
   emotionless, frigid, frosted, frosty, frozen, heartless, icy, ill,
   immovable, impassible, impassive, inexcitable, inhospitable,
   insusceptible, nonemotional, objective, obtuse, out of touch,
   passionless, self-absorbed, soulless, spiritless, unamiable,
   unbenign, unbenignant, uncompassionate, uncompassioned, uncordial,
   unemotional, unfeeling, ungenial, ungracious, unimpassioned,
   unimpressionable, unkind, unkindly, unloving, unpassionate,
   unresponding, unresponsive, unsusceptible, unsympathetic,
   unsympathizing, untouchable