Complex sentence: Sam's family disapproves of the relationship, so Ricky and Sam decide to elope to Gretna Green in 1991; they marry despite the Mitchells trying to stop the nuptials.
Split into simpler sentences: Sam's family deprecates of the relationship, so Ricky and Sam decide to elope to Gretna Green in 1991. They marry despite the Mitchells trying to stop the nuptials.