We introduce our new code, Smercury-T, which is a joining of the existing codes Smercury (Lissauer et al. 2012) and Mercury-T (Bolmont et al. 2015). The result is a mixed-variable symplectic N-body integrator that can compute the orbital and spin evolution of a planetary system under the effects of obliquity tides. We validate our implementation by comparing various experimental results to that of analytical models. Smercury-T will allow for the study of secular spin-orbit resonance crossings and captures within multi-planet systems while tides act to dampen the planet’s spin period and obliquity. These processes are likely important to the obliquity evolution of many bodies within the Solar System and beyond. We demonstrate a few cases of both non-chaotic and chaotic spin-orbit resonance crossings with the use of simple systems in order to clearly understand their effects.