Johnny & OTA
If it was a party and his girlfriend, no fiancee, was there, then naturally Johnny was there too. He liked an excuse to get dressed up, knew how good he looked in a suit and the one that had turned up for him was really perfectly his style. Sharp and designer and it might actually be better than the one he had ready for the wedding. He might want to swap it out.
Since Izzy was off shmoozing or whatever it was she was doing, Johnny was just going to have to make his own fun, and that meant he walked right up to the first person he saw alone after the dancing started and flashing a grin, offered his arm.