AITAH if I deactivate my Instagram that my girlfriend doesn’t know that I know she secretly logged into?

Yesterday at some point she used my phone and attempted to login by sending a link to my number (while she had my phone and must’ve done it successfully and deleted the messages. I can say with 100% certainty she used my phone as a way to login to my Instagram on HER phone behind my back when I was with her and I can prove it. Here’s the icing on the cake…we left our phones on the bed and I went back to get mine, see a phone ringing with my brother calling on Instagram audio. As I reach to pick it up I realize it’s her phone ringing, with my brother’s name...My brother doesn’t know her, they’ve never spoke and definitely don’t have each other’s social media. But on top of that, BOTH of our phones were ringing at the same time, showing an audio call from my brother on Instagram.

To suspend all disbelief I checked my recent logins and see a login from our location with a new device that is definitely not mine right around the time we got in yesterday. It’s the same phone model as hers. She’s had access to my phone throughout the day yesterday. Completely breached the trust, boundaries and privacy and she thinks I don’t know. I haven’t told her yet. It’s super deceptive and a extreme violating of privacy… it wasn’t an accident. She did it on purpose. My business and private messages with clients and friends and private story and everything is on there. I’m thinking about deactivating my account this morning and telling her Instagram was talking about detecting suspicious behavior and multiple logins and is questioning my account integrity.

Drag it out for the day and let her sit with that discomfort then just tell her whats up. Also want to see if she tells the truth once I share the edited screenshot with her. I’ve been suspended before so she already knows I have account issues (on top of being big on my privacy that we’ve had many conversations about) and pulled this. She doesn’t trust me and I understand that but this is a complete violation. Going through a phone is one thing but this is overboard. If she doesn’t trust me this much I’d rather her leave. I have a screenshot from an old suspension I’m I changed the old suspension date to today. AITA?