It does usually hurt - though on straightening the knee it will often resolve by itself. The more dislocations the less it seems to hurt. But continues to hurt.

In terms of therapy you should be working very hard the structures on the inside of your knee (VMO etc) and you could self mobilise your patella inwards to help stretch out any tightness of the lateral structures (though I don't give this often as a home exercise, but thats because I can do it for them in therapy)