Tease, don't roast
Light teasing works; meanness doesn't. The difference is you pick something they seem proud of and gently challenge it, not something they're insecure about. 'You ran a half marathon on a Tuesday? Okay, show-off.' works. Anything about looks or their ex doesn't.
Match tempo, then lead
If they send short replies, don't write paragraphs. If they send voice notes, consider one back. Matching tempo signals you're tuned in. Then, every third or fourth message, shift the beat — introduce a new topic or suggest a next step. That's how text moves to plans.