1. What does it mean?
Borrowed from football's tiki-taka passing style, 티키타카 can describe people trading remarks smoothly. Each person picks up the other's cue, keeping the conversation moving like a series of short passes.
Also written or said as 티키 타카, tikitaka, tiki-taka
2. The nuance
It is about the rhythm of an exchange, not necessarily flirting or agreement. Two friends can tease or debate with good 티키타카, but one person talking over the other is not the same thing.
3. Examples
“두 진행자의 티키타카가 좋아서 긴 방송도 지루하지 않았어.”
The two hosts had such good back-and-forth that even the long show wasn't boring.
“처음 만났는데도 티키타카가 잘돼서 시간이 금방 갔어.”
Even though we'd just met, the conversation flowed and the time flew by.
Sources
Kpedia: Korean language dictionary
References support the meaning and usage. Example sentences are written for NoCapWiki.