you can of course say those. Whatever is cruel can be called cruel. Cruel attitude, cruel italki, even cruel love. hoep this helps. :)

Here are some synonyms for the word "cruel" 1. brutal, ruthless, callous, sadistic, inhumane, hard, fell (archaic), severe, harsh, savage, grim, vicious, relentless, murderous, monstrous, unnatural, unkind, heartless, atrocious, inhuman, merciless, cold-blooded, malevolent, hellish, depraved, spiteful, brutish, bloodthirsty, remorseless, barbarous, pitiless, unfeeling, sanguinary, hard-hearted ,stony-hearted . Examples:1. The cruel practice of bullfighting. 2. The persecution of prisoners by cruel officers. 3. That was a cruel comment/comment about her new dress. 4. Your cruel heart will never understand my love for you.