stance change

I was caught between two extremes the other day and found myself changing my stance depending on the person I was with. I’ll give you an example. I was shopping with my mom the other day, and she happened to notice a red spot on my body and neck and said I had a rash. I told her it was nothing though she said it was a rash for sure. Then the next day, I was telling Jason that I had a rash, and he said it was only pink because I was scratching and it was nothing, and I argued that it was a rash for sure. I dismissed it as nothing with my mom and I argued it as something with Jason.

Why do I do this? And do others do this too?