The expression regarding Tasha doesn't go unnoticed by Steve. But he lets it go unmentioned.

As the kettle begins to whistle, Steve pours the hot water into the mugs, stirring the powder in. Jarvis would scold him for keeping powdered cocoa in such a manner, instead of having "real" hot chocolate, but this is exactly the sort of thing they had back in the war.

He hands the cup to Bucky, then offers his up in a toast.

Bucky's been gone a long, long time. He's been on a cold mission that tested him to his limits. And now he's back... and he gets to enjoy a cup of cocoa.

"To coming home," he offers with a smile.