Molecular dynamics (MD) simulations have been performed for solutions of two cross-associating chain molecular species (n-chains and p-chains) one of which (p-component) may contain both associative ("sticky") and inactive monomer links. The solutions of 63-mer chains show a crowding effect similar to that found in mixtures of short oligomers (J. Phys. Chem B, 2016, 120, 7234): the association equilibrium constant calculated from the stickers' concentrations increases with the volume fraction of the component with inactive fragments ("spacers"). For p-chains with inactive spacers of more than 3 monomer units, the equilibrium constant at a given concentration of p-component becomes almost independent of the spacer length. A simple mean field approximation for the excluded volume effect works reasonably well for the solutions of cross-associating chains except for mixtures with high concentration of p-component (C) 2017 Elsevier B.V. All rights reserved.