Characters are often drinking in the play, and how well one knocks ‘em back, is an indication of which side they fall on in the austerity vs. decadence game. Lepidus is weak, and needs to be carted off after drinking, whereas Antony is a heavy drinker, and can down them in sorrow and joy. He calls for wine when he celebrates with Cleopatra, when he’s been defeated at battle, and even when he’s dying. Caesar, by contrast, is the first to cut himself off at Pompey’s banquet, going home before getting out of control. He’s never really drunk in the play, as he thinks it makes his mind foul, and he criticizes Antony for his heavy drinking.
The play's central characters can be divided by their devotion to either passion or reason – personal characteristics that inform their actions. Caesar is all reason, all the time. He’s constantly planning and scheming, doesn't like to lose control through drinking too much, and he decries Antony’s decadent lifestyle. Cleopatra, by contrast, likes to wear nice things, drink nice wine, and lounge around in bed a lot. She is completely tempestuous in her feelings too, sometimes fawning over Antony, and sometimes scorning him. Caesar, however, is pretty consistent in his hatred and resentment of Antony. Antony represents a bridge between these two paths of reason and passion, or more accurately, he’s an emblem of the struggle between them. His passion keeps him in Egypt, while his reason calls him to the politics of Rome. Sometimes he is soldierly like a Roman, and sometimes decadent like an Egyptian. Where one falls on this continental divide is a big deal for figuring out what type of character one has. Antony, because he doesn’t clearly belong to either side, suffers a lot of self-doubt and judgment about whether he’s living his life well. It seems that it’s this uncertainty, or inability to honor both passion and reason, that ultimately defeats him.
"Just kidding" is a really wonderful little device that Shakespeare uses to communicate to us just how flip Cleopatra often is. When she loses Antony in Act I, Scene iii, she tells Charmian to report back to her on whether Antony is well or not. If he’s well, Charmian should report that Cleopatra is very ill (and implicitly needs his attention), and if he’s not so well, then Charmian should report Cleopatra is happy and dancing (meaning he should go pay attention to her, because she doesn’t care about him). This kind of constant back and forth characterizes much of Cleopatra’s speech, and is her way of gauging Antony’s feelings for her. It is not insignificant because it precipitates one of the play’s climactic moments, when Antony chooses to kill himself. Cleopatra has her servant communicate to Antony that she’s killed herself, just to see how he’ll react. Great, except he reacts by killing himself.