The (B) over tilde (1)A(1) state of SiH₂ and SiD₂ was observed by the optical-optical double resonance technique for the first time. The electronic band origin of the (B) over tilde state of SiD₂ was determined to be 27 214.11 cm^-1. A very clear exclusive behavior depending on the even/odd value of the bending vibrational quantum number was observed in the spectra, representing a quasilinear behavior of the (B) over tilde state. The barrier height to linearity was estimated to be similar to 125 cm^-1 by the quasilinear analysis of the bending vibrational level structure of SiD₂.