Let R be a commutative ring with nonzero unit, and \(\delta \) an expansion function of its ideals. In this paper, we introduce sdf-absorbing \(\delta \) -primary ideals. A proper ideal I of R is termed square-difference factor absorbing \(\delta \) -primary (sdf-absorbing \(\delta \) -primary) if, for all \(0 \ne a, b \in R\) with \(a^2 - b^2 \in I\) , it follows that \(a + b \in I\) or \(a - b \in \delta (I)\) . Several properties and results are presented and supported by illustrative examples showing, in particular, the nontrivial nature of the introduced class. Moreover, we examine the transfer of sdf-absorbing \(\delta \) -primary ideals under ring homomorphisms, and their behavior across various fundamental ring-theoretic constructions, including localization rings, polynomial rings, product rings, trivial ring extensions and amalgamated rings.