Shikamaru and Temari are getting ready for their wedding. Because Temari is a sibling of the Kazekage and Shikamaru is an influential figure in Konoha, their marriage is a delicate political matter that will solidify peace between their two villages. In the midst of careful consideration, Temari and Shikamaru are trying to find a date for their wedding that will appease both sides.
The fact that their children will be raised in Konoha, but will have the Kazekage bloodline and therefore would be in line to be Suna's next Kazekages, is what makes the Suna elders arrange a marriage for Gaara.