If Tully really is single she can do what she wants, and I think she must be single from what she says and does. I want to see photos of her with other HM's etc.
If I was Drew and saw her flirting with Ed/Nick it would make me feel uncomfortable(because it's Ed), so it leads me to believe they aren't together... but maybe they gave it another go though.
As far as Drew seems concerned there was a article in OK months ago saying they split up and but remained close friends, so guess he doesn't have to announce anything, if that was still the case.
it's us that speculate that they are FWB etc when Tully constantly says she is single, and looking to date someone.