AITAH for "Cheating" on my Wife

Hey reddit, throw away because I don't want this story associated with my main account.

So some background. I (M, 35) and my wife (34F) have been happily married for 11 years, have a child together and I am desperately in love with her. We both practice Christianity, and are very devout to our beliefs.

Recently my wife has been quite busy with work and school, as she is finishing up her degree to be a lawyer and then has been studying for the Bar exam. She has been heavily invested in to her studies, studying most weeks for nearly 25 hours on top of her full time job and interning.

I know this can make me seem like a bit of a bum in comparison to her but please know I also am working a full time job in addition to multiple side hustles. Life is expensive living in Cali.

I say all of this to help understand the "cheating". One day we were having a busy morning. I was getting my son out the door to school and she was rushing around to get to work. After my son got in the bus, my wife left for work right after him. I had the morning off. I was feeling a little frisky so I pulled out my phone and pulled up a spicy video my wife and I made a out 7 years ago during intimacy.

So here I am watching the video and beginning to pleasure myself. The sound then disconnects (later finding out my wife had come back home to get her phone and it connected to her car audio) I then fixed the sound so I go back to doing the deed. As I am finishing my wife walks in on me furious.

She asked me what the heck I was doing and how could I do this to her. I sat there ashamed but a little confused and after her ranting rage I said I didn't see what the big deal was. She said you're watching porn and pleasuring yourself to it. Then went off on a short tangent about knowing I wasn't attracted to her anymore. I then flipped my phone to her to show her the video I was doing the deed to. She then was furious with me still. I said I still find her incredibly attractive and find her even more beautiful now (actual truth) compared to this 7 year old video. She then insisted I was cheating on her because I was pleasuring myself without her. I sat there naked and shocked.

I asked her how it was cheating. She then said because sex is to be a together act. I asked her if she thought masturbating was wrong, and let her know that there have been times during intimacy that masturbation was an act we did. She said that it wasn't wrong but that it still needed to be done together. I explained to her that I didn't see anything wrong with it, I wasn't watching other women and would rather be having sex with her then watching the video but I was just feeling "backed up" and that it has been a few weeks. She then was furious and essentially left for work. So here I am wondering what I did. I asked her why she agreed to making the video then and what she thought I was doing with it. She got more mad and then went to work. So here I sit wondering AITAH?