What are the limitations on judicial discretion on costs when settlement offers aren’t accepted

Trial judge erred in duration of spousal support award and spousal support was ordered on indefinite basis; Although trial judge did not expressly make finding of entitlement on compensatory basis, he functionally did just that

Parties were in relationship for eight years, but nature of relationship was at issue. Evidence was clear that parties dated for long time, but they never established common-law relationship.