How do you re heat cream sauce so that it doesn't separate (butter separates!)?

I usually microwave, and the butter separates from the rest and looks all greasy! PLEASE HELP!How do you re heat cream sauce so that it doesn't separate (butter separates!)?
Sounds like it's breaking. If you want to bring it back, make a small cream sauce batch and add it slowly to it or just add more roux or wondra or flour.How do you re heat cream sauce so that it doesn't separate (butter separates!)?
gentle reheating is the answer - microwave is not
I usually reheat cream sauces in a saucepan over very low heat. Stir often. There is still a little bit of separation, but nothing like using the microwave.
Do exactly what you said, REHEAT. It means, you heat it up on very low. You don't let it boil. Mixing, stirring is also advised.