My goodness, these proms do attract some strange behaviour don't they?
In this particular case, wouldn't it be wonderful if it were just the Proms?
Russky-au-lait can be found at virtually every symphony concert and opera performance in any London venue, all year round. In fact, we are convinced he has managed to clone himself, as he's EVERYWHERE.
It is generally possible to avoid him by booking tickets in the SECOND-from-cheapest price band at any given event. Hint: steer well clear of rear-Amphitheatre standing places at the Royal Opera House - and of the stage door afterwards.