We introduce the two-particle probability density X(x) of x = r12 · p12 = (r1 − r2) · (p1 − p2). We show how to derive X(x), which we call the Posmom intracule, from the many-particle wavefunction. We contrast it with the Dot intracule [Y. A. Bernard, D. L. Crittenden, P. M. W. Gill, Phys. Chem. Chem. Phys., 10, 3447 (2008)] which can be derived from the Wigner distribution and show the relationships between the Posmom intracule and the one-particle Posmom density [Y. A. Bernard, D. L. Crittenden, P. M. W. Gill, J. Phys. Chem. A, 114, 11984 (2010)]. To illustrate the usefulness of X(x), we construct and discuss it for a number of two-electron systems.