As I understand it this is where the whole protocol issue comes into its own. As my learning may be a bit old-fashioned I can't be sure it applies these days, but it should.

If you have an agreement with a Dom[me] (i.e. any kind of relationship up to and including being owned) no-one else has any right to "Dom" you without permission from your own Dom[me]. Should this happen, e.g. you are requested to serve, protocol dictates you give something like the following response:

"I respectfully apologise Sir (or Miss or Ma'am) but I am protected by Vampire and am not allowed to serve anyone else"

There is also the protection rule in protocol, which means if you are repeatedly harrassed (e.g. three times) you can then go to another Dom[me] and ask for protection - your protector should then confront any other Dom[me] who tries to "take" you.

Of course, as with anything in our lifestyle communication is extremely important - so discussing this point with Vampire is a must - also when you go to a munch I suggest you check with the organisers that protocol is recognised there.

Hoping this helps
VV