I [22M] can’t stop thinking about my best friend [21F] and her bf, am I a cuckold?

TL;DR: Already obsessed with my best friend, saw her hot selfies and a video of her kissing her boyfriend, now I get turned on by thinking of her with her boyfriend. What do I do? Am I a cuckold?

So, I've been best friends with this girl, for years. We've known each other since high school and have been through a lot together. Always thought she was cute, but I never really saw her in that way. But lately, things have changed.

I don't know what happened, but suddenly, I started noticing her in a different way. Her smile, her laugh, the way she moves, it's like I'm seeing her for the first time. I tried to push these feelings aside, told myself it was just a phase, but it only got worse.

Then, a few days ago, she left her iPad at my place. I was bored, and the curiosity got the worst out of me so I decided to scroll through some of her photos. I saw her. In her selfies, she looked… damn, she looked hot. Her eyes were sparkling, her smile was infectious, and her body… man, her body looked incredible.

I couldn't look away. My heart was racing, and I could feel my body reacting in ways I hadn't expected. I started getting hard just looking at her photos, imagining her touching me, kissing me, being with me. It was crazy, man. I couldn't focus on anything else. My mind was consumed by her, by the images, by the desire.

But then, I stumbled upon a small, dumb video. It was of her and her boyfriend kissing. Seeing her with him, the way they were kissing, it did something to me. It made me hard, and I couldn't stop thinking about it. I found myself wondering if it was like cuckold stuff, you know? Seeing her with someone else, knowing she's with someone else, but still wanting her so badly.

I know I should resist, but I can't. I'm drawn to her in a way I've never been drawn to anyone else. It's like I'm addicted to the thought of her, to the idea of being with her. I can't stop thinking about her, can't stop wanting her. And I can't get that video out of my head and now everytime I see them give each other a little kiss it turns me on. I want to watch more and I want to see all her selfies she's so hot.