They finally took the court together last month, when New Zealand hosted South Korea in a three-game series, and have combined throughout the Tall Blacks' tours of Asia and Europe in the lead-up to the World Cup.
Corey top-scored in two of New Zealand's five games in Europe, and Tai saved his best performance for last, scoring 21 points in the Tall Blacks' upset win over Serbia to cap their preparations.
While he's pinching himself at getting the chance to play at a World Cup as a teenager, Tai has always dreamed of playing internationally. Basketball was a big part of his childhood, with his dad Tony an NBL stalwart.
"Ever since I could walk, I have been shooting around at halftime of big bro's games or dad's games," he said. "I've been around basketball my whole life. I couldn't get away from it."
The 25-year-old Corey is a proud big brother and is comfortable coming off the bench.
"It's all good. It's sport, that's what happens. All of the positions are different and everyone has a different role," he said.
"It's awesome to see how he's grown up and how much better he's got going overseas and playing in college."
Tai had an underwhelming first season at the University of Nebraska, averaging just 3.9 points per game on 30 per cent shooting. But Tall Blacks coach Nenad Vucinic likes his athleticism, which has seen him get the nod over the experienced Lindsay Tait as the starting point guard.
"I wouldn't say I'm ahead of Lindsay or anything," Tai said. "I just think I bring a bit of pace to the line-up and Nenad wants that from the point guard."
Assistant coach Paul Henare, himself a former Tall Blacks point guard, says the Webster brothers have become a huge part of the team.
"They both bring a different style to what New Zealand's had in the past, which gives us a better foot to stand on against these tougher sides," Henare said.
He is also envious of what the brothers are capable of on court.
"They're far more talented, far better than I ever was or hoped to be."
They attended Westlake Boys' High School, where half the Tall Blacks' 12-strong squad were educated, including veteran shooting guard Kirk Penney.