Short rejection lines like this spread online as reusable reaction audio, shared between chats and reposted in meme edits where the context is a flirty setup and an instant shutdown. The bf abbreviation keeps the phrase in the casual language of texts and comments, which helps it fit dating jokes, fake confession skits and friend group teasing. Its brevity is part of its appeal, as the whole joke lands in about two seconds without needing explanation, so creators can drop it into many different scenes.