First night: no, I don't think so. The way she blows him a kiss from the stage in the teaser looked to me as if they had already been physically intimate at this point. On the other hand, I think Trakis didn't find out, he knew from the start. He asks "how are things going with the ambassador?", not "So, I hear you're seeing the ambassador". IMO he either told Adira outright to start an affair with Londo or he immediately pounced after seeing that Londo was interested, because he probably was after those files - and revenge on the Centauri - from the get-go.