Both. I looked up the tavros prerequisites
*ship at Tavros
* 10% kaede Exhibition minimum
* met kaede
* slept with anno
* had the anons bar threesome
* last threesome was at least 7 days ago
* 1/10 chance of triggering
If you want to trigger it, just go to anno on the ship and leave again if nothimg happens. If you can't trigger it, send me your save and I'll have a look