As the NBA prepares for the arrival of team guests into The Bubble for the start of the conference semifinals this month, the league is requiring players provide proof of “longstanding relationships” with non-family members, according to a memo obtained by ESPN. The NBA and National Basketball Players Association negotiated terms that preclude players from hosting guests who’d be deemed as wholly casual in nature, including “known by the player only through social media or an intermediary,” according to the memo.