x1 is a step-parent via the mother of x2 due to marriage with the latter's mother according to law/custom x3, where said motherhood is not necessarily biological.
x1 does not necessarily raise x2 (for such a purpose, append "rirni" vel sim. as a tertau). The gender of x1 is not specified. See also: "pa'uspe", rirspe, spemamta.