There's a scene in one of the first two Star Wars movies, where Han Solo says, "I have a bad feeling about this." That's exactly what I'm saying to myself right now.
How do you know she's not going to leave you suddenly one day for another "old guy?" (I'm about the same age as you, BTW.)
What's the term I'm thinking of? Catfishing? Except in person... Someone help me out. I'm genuinely concerned for you!