I feel like my gf does this. Especially after a fight we have, she will act normal, try to engage, smile, laugh and act happy. Then a few days later its like she doesn't even want to look at me. I brought it up once in a fight and she said "its just that i want to be alone sometimes." But it could happen in a day. Like. Lets say we had a great morning, we went out to a park, or even to the store and all of a sudden its like she switches. If i ask her whats wrong she'll say "no". Then I ask "why are you acting like this" she says "acting like what?" Or "im not acting like anything" I'll say you're acting different.
Just denies it and acts like she has no idea what im talking about. As if I'm imagining it. Now if. Dont accept her answer she'll start getting irritated. If i get a little heated she immediately just starts arguing/ denying, the more i point out that she does infact switch like this, she'll argue and deny.
Im pretty observant so i know I'm not imagining it, im not crazy. Most times i just ignore this behavior because, idk i occupy myself with other stuff. But i still notice it.
Maybe she does this because shes insecure. Maybe its for drama. Idk. She doesn't drink, smoke or do drugs and i dont think she ever has.