At the risk of offering a sensible response, grow up.
We all have this situation to face at some point in our life, so do what the rest of us do: be polite, enquire after her health, shake her husband by the hand, and then walk away. No need to have this massive hangup.
She's moved on; you've not. You need to face the fact that the only person worried about meeting anyone is you. The fact that she's married points out the fact that she's almost certainly not spent the time pining after you the way you have after her.
Don't get pissed/hire a hooker/preted to have inherited a title. She'll think you're a dick, which will only add to your torment.
Oh, and once this is over, find yourself a real girlfriend, one you can actually spend time with in the here and now, rather than worrying about someone you split with 7 years back.
