The relationships of Bruce Banner/Hulk.
Romances
Betty Ross
Betty was Bruce Banner's girlfriend. Betty and Bruce were sweethearts in college, which marked the time Banner became the Hulk. Both Hulk and Banner personalities care deeply for Betty and will go to great lengths to make sure she is safe. She still remained by his side when he became Hulk, and they bonded over the fact that she was the sole individual, who had no intention of hurting him. They mysteriously broke up before the Battle of New York. However, Hulk saved her life when he undid Thanos' snap.
Natasha Romanoff/Black Widow
Both Hulk and Banner were in love with Black Widow, but their romance was short-lived, as he fled the planet and was absent for two years. After his return, they reunite but seem to have distanced from each other as they are not seen interacting much afterwards. Despite this, Banner still shows signs that he still has feelings for her. Five years after Thanos' snap, when Natasha sacrifices herself for Hawkeye to obtain the Soul Stone, Banner mourns for her. Sometime later, he reveals to Steve that when he used the Infinity Gauntlet to bring back all the life that Thanos erased, he also tried to revive Natasha, but was not successful.
Family
Jennifer Walters/She-Hulk
Jennifer Walters is Bruce's cousin, who is introduced as the titular protagonist of She-Hulk: Attorney at Law. Jennifer gets infected with the Hulk's blood after a car crash and Bruce, as the Hulk, helps her deal with rage and how to handle having the Hulk attitude. They are shown to be close as Bruce teaches Jennifer skills that come with being a hulk, and they are seen enjoying spending time together.
Friends and Allies
Tony Stark/Iron Man
Banner has a very close relationship with Iron Man, they normally work together and are able to relate to each other because they are both brilliant scientists. They both respect each other and Tony shows great concern for Bruce due to his alter-ego as the Hulk as shown in the first two Avengers films. Tony also explains his worries and PTSD to Bruce after the events of the Battle of New York. Bruce is also the one who confines in Tony the most when he informs him about Thanos' quest for the Infinity Stones.
Thor Odinson
He has a love-hate relationship with Thor, having beaten him up, but he later becomes friendly towards him when the two meet on Sakaar and they spend time on the planet together with Valkyrie. Banner also became closer to Thor during their encounter on Sakaar, and they planned together their escape from the planet to go confront Thor's older sister, Hela, at Asgard.
Steve Rogers/Captain America
The Hulk seems to respect Captain America as he listens and follows his instructions during the battle of New York while Banner considers him a friend as a fellow avenger.
Valkyrie
Valkyrie was the closest friend that Hulk had during the two years he was on Sakaar, they were both very friendly and playful with each other. When Hulk finally reverts back to his Bruce Banner persona, neither Bruce nor Valkyrie recognize each other, but they both also have the impression that they know each other from somewhere. Despite of this, Banner and Valkyrie become friends while they plan to escape the planet to go confront Hela at Asgard. During their fight against Hela, Valkyrie is very surprised when Banner decides to transform to confront Fenris Wolf, revealing to her that he was the Hulk all along.
Enemies
Thaddeus Ross
General Ross is Hulk's enemy. Ross was so obsessed in capturing the Hulk using whatever means necessary, which caused Hulk to hate him.