Ese tipo es un cabron (Spanish)
Hey cabron! (Hey dude)
Mira cabron (Spanish)
That damn cabron (insulting)
Ese cabron (Spanish)
Ese disco nuevo esta cabron (nice)
The hand gesture is the first and fourth fingers extended, the others tucked in so as to make horns at someone. "Horned" is the term for "cuckold/cuckolded" in Latin countries where there are a gazillion jokes about poor, predestined husbands named Cornelius.
"Keras" in Greek and "cornu" in Latin were metaphors of power, strength and domination since stags, rams and bulls were all horned and showed those qualities. Later on, both "keras" and "cornu" came to be slang terms for the penis in Greek and Latin, and "corno" still is in Italian.
To put the horns on a husband is not only to be his sexual surrogate, but also to reduce him to a passive and ineffectual role.