Originally Posted by M-2
Well they don't have to go straight into the whole romantic angle with Black Widow and Winter Soldier... I think Balck Widow can be used to ground the terror that is The Winter Solider, while through Cap you get that shock of seeing his closest friend from his WW2 days still alive!!
In Avengers we did see her mention that she had red in a ledger, hopefully some of those things she did was with the Winter Soldier!! So when his introduced, you actually see the fear in eyes and it's like "this ish just got serious" type thing!!
Just making mention of her possibly working with WS or even having knowledge of him would be good enough to connect the MCU.