Hi again Wrpword, By stage I presume you mean theatre.
You would have to be careful about using the word 'escort'. Although it is technically correct it has taken on other meanings these days. It can imply a 'companion-for-hire', which I don't think you mean here. You could use the word 'companion' (though not for hire of course) or ' the person accompanying the guest. It all depends on the actual sentence you have in mind.