However, Mark Ruffalo does imply that this is something the pair will be “dealing with” for a long time, so you can expect the item to at least be brought up during the events of Avengers: Infinity War.
Referring to the relationship between Black Widow and Bruce Banner as “star-crossed” is not a good sign, as that implies the relationship between the two is fated to fail.
Seeing such a relationship work out would be a long shot at best.
One of them is a trained assassin and the other turns into a big green monster every time his emotions get the better of him.