orlando ships david with gillian because he knows it’s a bit of fun and not real. he’s pandering to the fans. if they were in a real relationship that they’re trying to keep on the down-low, he’s not gonna be spreading that shit around on twitter. gillian and david probably don’t care because they know the truth of the situation and it’s of no consequence to them.

I think he doesn’t really know what’s going on between them, but I think he smells the fuckery like the rest of us, and probably more. Maybe he has witnessed things that drove him crazy. But in any case I think he’d do that if he knew one of them was in a serious relationship with someone else.
He’s not a basic fan, he knows them, so I don’t think he would go there if he thought it could hurt someone.