Ok, I hope I'm not out of line here - never been in this particular thread, but...how can I say this tactfully - I've been around the block a few times, relationship-wise. So, I'll slide my 2 cents over and you can accept it or just skip over it.
First of all, sorry about the divorce. No matter how badly you want out of a marriage, it still hurts. If you don't have any children - count yourself lucky. If you DO have children together - just realize that your marriage will NOT be over until those kids are grown (and not even then, but it gets easier).
As for this friend of yours that you're having lunch with that "forgot" your birthday and then tried to lie about having sent flowers. Well, Nancy - it does ring all sorts of passive/aggressive bells. Being late, neglecting to confirm a date, forgeting important dates, trying to lie your way out of a situation - bottom line is that YOU aren't important enough for him to make an effort. Sad but true. And right now you have no control over the situation. (Don't get me wrong, he's probably a nice guy, but we're thinking about NANCY here). My recommendation? Back off a little. Don't call him, if he wants to have lunch, he knows your number. Don't mention your birthday again, in fact AVOID the subject. Then go out an get yourself a whacking good massage or facial. YOU need to take care of YOU. If you let 'em, men will spin you up so fast that you'll get whiplash.
One last thing - all my experience boiled into one sentence. The ONLY qualities required in a mate are generosity and integrity. Think about it - everything else is affected by those two traits.