Is this okay/legal?

My husband and I have been seperated for 4 weeks now. Prior to that he has been communicating with a girl that he denies until now. He would talk hours on end with her. Now that I have moved back to MA with our 3 kids, he is now moving her into our home with him and said our girls will be around her no matter what. I feel this is not healthy for the girls to have to go back to “our familys” old home and see her and him and her daughter with all their stuff in our girls rooms etc. He has a pending felony charge of assault on me and i have temp custody of the girls for 1 year. She also kicked her father of her daughter out the same week he kicked me out.
Is this legal what he is doing?
Is this considered adulterous?
Alienation of Affection?
Where to i go from here and what can i do?
Thankyou sooo very much!!

He can move her into the home as he has the right to exclusively posses the home since you moved. If he is having sex with this woman the behavior is adulterous.
You may have a claim for alienation of affection against her if she is the reason the affections of the marriage were destroyed.
You can file for permanent custody in NC, and seek a provision in your Order that the children be kept away from this woman when your ex does get visitation.

Would I file now for permanent custody since my temporary full custody just started or would i wait until 1 year from now? There is nothing set for visitations through the court. Is it illegal to have him come to MA to visit the girls instead of him having them stay in that house with this woman and himself and her child? Do I need a lawyer to do all this? Alientation of Affection, File for permanant custody?

Thankyou

You would file for permanent custody now. It is not illegal for you to have him come to MA to visit the children so long as the order does not require the visitation to occur in NC. You can proceed without an attorney on both claims, but if possible I suggest you hire counsel if possible.