You want some? I don't have that much to spare nowadays, but here goes:
Ditto stillalone3, treat your H like you would a good friend. That serves to guide you in answering your latest question:
Now do I call him and tell him forget about skipping tae kwon do since the girls will be busy with their friends? Or do I tell him the girls are having friends over but if he still wants to skip TKD to just spend the time with me that would be ok too?
I don't know about you, but if your H were my friend, I'd advise him of the change in circumstances and then leave it up to him to figure out his options and decide what he wants to do.
Just don't want it to backfire and have him then say, well guess I'll just go to TKD then.
And if you leave it up to him to think for himself, nothing will backfire... but never act based on what you think another's reaction is bound to be or what their thoughts may be. When you do that, you're making an assumption and you may be totally wrong. And then what additionally happens when you act based on imagined future scenarios is that you automatically cancel out what real life would've brought about, which may be just the thing your sitch needs. Life dishes out results in ways that we don't always see coming out our situations.
