Was she one of those women who whore themselves out to prisoners because they can't find people who aren't stuck behind bars, sexually frustrated with only several thousand other penises to keep them company?
What were you in for, Repo?
Either way, even though we can't actually prove she has been fucking around on you lets assume that she is anyway because it's far more entertaining this way. Now, if I were you I'd go on as normal for the time being. Continue to make plans for her inevitable move over to the sunny Isle of Britain so that you could both get on the back of your noble steed and ride off into the murky, overcast distance.
But (and here's where we start the fire), when the time does come when she finally feels it's right to come over to to start a new life with you, try to forgo giving her your address and make it plainly clear that she'll find out all when you pick her up from the airport and she settles in.
Then, when the day finally comes, don't show up.
Maybe as an added kick in the teeth, get someone you know to rob her. Leaving her stranded and alone in a foreign country without the means to get home.
I'm sure you'll feel much better upon receiving the first angry email from her once she has finally made it back to wherever the fuck she's from.
Godspeed.