Don’t.

In the meantime, check out this advice column (<link>) over at Salon. Pay especial attention to the letters from readers. While I warrant that your situation is different than the LW’s, the fact is, passion comes from within. You bring passion to a relationship, it doesn’t magically spring up out of the ground, especially between people who have been together for years.

More importantly, every relationship eventually runs free of passion. Did you ever occur to you that the reason you’re so attached to your high school sweetheart is because the thrill is new and exciting, and the POTENTIAL for the relationship is an all consuming force? You haven’t seen this man in person since you were a teenager… so the fantasies of what you could have with him are completely unfounded in real life.

Lastly, get thyself to a marriage counselor. The way you describe it, your marriage doesn’t sound bad… just passionless. The one with a problem here is you, and your need for excitement. By pouring all of your attention into someone else, you’re actually sapping your marriage of whatever passion potential it might have, because you’re busy focusing elsewhere instead of building something with your partner.

So, in conclusion… don’t.

PS: His whole line about “I’m happy but be patient” is complete bait and switch. He could have you waiting for months, years, decades. You are merely his backup plan, sweetheart, for whenever his wife doesn’t happen to make him happy. Is that really the sort of partner you want?