I guess it depends on how often this happens and more to the point, does he injure her?
My two do this still, almost 2 years on, even though we got them as rescues together! They do play fight every now and then but they never hurt each other, thank God! (I've never had to take them to vets because of it!)
My 2 do respond to a firm no but this isn't a daily thing, so it does depend on the frequency?!
The funny thing is, they do sleep together side by side occasionally and they also groom each other's face, which is so cute to watch, so I'm pretty sure they don't hate each other!
Just keep an eye on the situation and I hope you don't need to re-home either as the British Blue's are really cute cats but I have been told they can be temperamental creatures at times!!
Good luck!