Mirroring back the behaviour they think is expected to gain aproval. It took me a long time to see that my stpdtr did not have my morals and code but was only mimicing me. She says and does what she thinks is wanted because she dosn't know what to do herself. She says, "when I see you, how do you want me to act?" or "I am not sure how you want me to respond to that".
I experienced mirroring before I found this site. After my uBPDxw ran out in my sons and I after 18 yrs of marriage she completely stopped going to any church. I asked her why she doesn't go any more and she said "I only went because I knew it was important to me"... . Really? For 18 years?
I didn't realize it when she said it but she was admitting to mirroring even though I'm sure she's not aware she's a pwBPD.