Spock-Prime picks up the pieces from Spock's rejection.
Weird alien magic leads to Kirk being pregnant with Spock's child (adding insult to injury, no sex was involved). Spock, happy with Uhura and not interested in a closer relationship with Kirk, wants nothing to do with it. Kirk ends up staying with Selik (the older version of Spock from an alternate reality) ... and it's not long before Kirk realizes he's definitely traded up.