He wrote a little waltz-song, which he would sing and play to his current dating partner.  It was, in effect, what his friend Kitty Carlisle (who later married playwright Moss Hart) described as his “mating call”, because he left a blank space in the lyrics so that any name could be inserted – and of course varied according to which girl he was trying to impress.  At one party he was getting along famously, cuddling an attractive companion on his lap, when someone asked him to play the piano.  His electrifying dash to the keyboard meant that the astonished woman found herself dumped on the carpet.