Assembly and method of fabricating an assembly including an extruded polymeric tube and a prefabricated tubular polymer body (fitment) the method including the steps of: extruding an outer tubular surface of a thermoplastic propylene based elastomer (PBE) material treating the outer surface along a selected axial length at one end of the tube with a solvent inserting the treated one end into a hollow tubular passage of a prefabricated tubular body having an inner passage wall of a polypropylene based material and allowing the mated juncture to dry such that the treated outer surface solvent bonds to the inner wall. The tubing is preferably a coextruded tube having an innermost layer of a thermoplastic ethylene based olefinic material. The mating tubing and fitment overcome the prior art problems of stress cracking fluid contamination and/or processing difficulties.