User blog comment:Hulk10/Bruce and Natasha lovers/@comment-24675861-20150305215427

Trailer 2 - Natasha and Hulk touch hands as they stare at one another. Banner and Romanoff sit together during the Lift Mjolnir party.

Trailer 3 - Natasha and Bruce are together in a house. She has on a bathrobe. She snuggles close to him as they talk.

I think they are lovers, at least friends with benefits. Banner must have conquered that heart rate problem he had with Betty...