Science Boyfriends

Science Boyfriends is the slash ship between Bruce Banner and Tony Stark from the Avengers fandom.

Canon
The Avengers

Tony and Bruce first met aboard the S.H.I.E.L.D. helicarrier. They worked together to find the missing Tesseract. Tony tried to convince Bruce that the Hulk wasn't such a bad thing, and that he should fight alongside them. Though Bruce initially refused to, he relented and fought alongside Tony as the Hulk in the Battle of New York.

Iron Man 3

Tony tried to vent his traumas to Bruce, but Bruce fell asleep, later telling Tony that he's not that type of doctor.

Avengers: Age of Ultron

Tony and Bruce were working together on the Ultron Program, a global peacekeeping program. After they retrieved Loki's scepter from the HYDRA facility in Sokovia, the two discovered that the scepter held a form of artificial intelligence. Tony convinced Bruce to use that A.I. to power Ultron, a decision that would soon prove to be disastrous.

Later, while the Avengers fought Ultron's bots in South Africa, Wanda Maximoff used her mental manipulation power to force Bruce to turn into the Hulk and rampage through Johannesburg. Tony equipped his Hulkbuster armor and tried to contain and talk the Hulk down. When that failed, Tony resorted to fighting him. After a lengthy battle, Tony managed to knock him unconscious.

After Clint Barton returned to Avengers Tower with Ultron's unfinished synthetic body, Tony convinced Bruce to help him complete it rather than destroy it, using J.A.R.V.I.S. as its mind this time. Though Steve Rogers and the Maximoff twins tried to stop them, with the help of Thor's lightning, they were able to complete it and create the Vision. Tony and the Hulk fought alongside each other during the Battle of Sokovia.

Avengers: Infinity War

After being teleported to Earth by Heimdall and crashing through the roof of the New York Sanctum, Bruce informed Stephen Strange and Wong of the impending threat of Thanos. Stephen then contacted Tony for help. Bruce hugged Tony upon seeing him for the first time in years.

Bruce tried to convince Tony to call Steve Rogers to help find Vision, but before he could, Cull Obsidian and Ebony Maw arrived. Bruce, unable to turn into the Hulk, was stuck on the sidelines as Tony, Stephen, Wong, and later Peter Parker fought the Black Order. Bruce and Tony both survived Thanos' snap to kill half the universe.

Fandom
AO3

Variations

 * Science Bros refers to Bruce and Tony as close friends.
 * Science Family refers to Bruce and Tony's established family life usually including Peter Parker as their adopted child.
 * Stark Spangled Banner refers to a poly relationship including Steve Rogers