Saying “I love you” too fast, red flag?

Yelena

I was casually scrolling through tik tok and saw one about red flags. The girl mentioned that saying Ily too fast is a red flag, I went through the comments to understand why but I’m not getting it. And basically the boy I’m talking now did the same thing. He said ily on like the 3rd date but everything has been going to great. Let’s also take into consideration that I’ve known him for 3 years, we talked once or twice before but I’m a sucker for ghosting people(sorry) 😭. When he said it I was completely shocked/went into panic mode but at the same time it didn’t feel out of place. And so far we’ve been doing great, it’s at like a steady fast pace. And it’s like he’s my second half, and I don’t catch feelings for people at all. Idk is it a red flag?