A few days ago, I told my friend I had a crush on her, but I didn't wanna pursue it because she always makes it clear to me and our other friends that she doesn't like relationships and isn't looking to be in one. When I told her, she repeated this AND said that if she was looking to date, she would consider giving me a chance. We were cool with each other after this.

Today, I'm in our group chat, and this random guy and her are acting all "lovey" towards each other, and everyone else is saying they're gonna get married as a joke. My brain was telling me what was happening, but I was praying it wasn't what I thought it was...until someone confirmed they were dating. I went inactive, and I left the group chat an hour later. I speak to her friend, and she told me they've been together for a while, and definitely before when I told her I had a crush on her.

She texted me soon after, asking why I left the group chat, and if it was because I found out. She then asked me to "please talk to her". I've left her on delivered and I don't want to respond. I really value our relationship, but I'm also really hurt that she lied about not being in a relationship to me, and I don't think my jealousy could handle seeing her and her boyfriend being all "lovey" in the group chat.

AITAH? Also some advice on how to handle the situation would be nice.