Entender
To be gay/lesbian. Usually seen as a question, used in the Spanish LGTB scene.
Entender --------> ¿Entiendes?
double entender
Refers to where someone acts "all nicey-nice" --- i.e., kind and caringly-gentle --- as if he has genuine loving feelings for you, but in reality he is merely "turning on da charm" in an attempt to disarm/dispel your natural caution/inhibitions so dat hopefully you'll let him get in your pants.
People like Clinton and Liberace were masters of da ol' "double entender" dat did indeed sometimes please and/or flatter, but you see what kind of messy misbehavior they ended up committing.