Hi Jo, Stay with one thread, would you? Otherwise, folks lose you or some detail.
Five mo is a long time to be dating in "secret." It seems like an odd request, and you are right to be balking at being some sort of "mistress." Maybe just let him know that you're not going to place an advertisement to announce it, but you also refuse to hide your wonderful R anymore.
I'd avoid artificial deadlines - it adds unnecessary pressure and it will violate your integrity now if it is reached and you go against it.
Overall, nice changes though. Keep the Rs with the kids as a very high priority, as separate from your and H's R outcome as possible.They deserve you and you them no matter what. Dont let nasty messages keep you away from them. Kids are smarter than that, and figure the truth out very quickly. Focus solely on them when with them, not on H (unless he's around as well).