Anybody have Trouble with there bfs mom or mother in law just found out that she thinks since I…

Anybody have Trouble with there bfs mom or mother in law just found out that she thinks since I cheated on a guy once that Ima cheat on her son and to top it off she thinks that's not her grandson still until he's born and we do a dna test!!! I thought me and his mom were cool but she a two face and I'm done with her my man even thought she being ridiculouse but whatever she can think all she wants 😡