He always acts as if he's making a fool of me.
Please stop talking to me like I'm beneath contempt.
馬鹿 is a more common and versatile word for 'fool' or 'idiot', while 小馬鹿 is mainly used in the set phrase 小馬鹿にする.
Standard kanji spelling.
Mixed kanji-kana spelling.
Rarely used kanji form.
Compound of 小 (small, petty) and 馬鹿 (fool). The exact historical derivation is uncertain, but it likely developed as an emphatic or nuanced form of 馬鹿.