  Microresonator-based nonlinear processes are fundamental to applications
including microcomb generation, parametric frequency conversion, and harmonics
generation. While nonlinear processes involving either second- ($\chi^{(2)}$)
or third- $\chi^{(3)}$) order nonlinearity have been extensively studied, the
interaction between these two basic nonlinear processes has seldom been
reported. In this letter, we demonstrate a coherent interplay between second-
and third- order nonlinear processes. The parametric ($\chi^{(2)})$ coupling to
a lossy ancillary mode shortens the lifetime of the target photonic mode and
suppresses its density of states, preventing the photon emissions into the
target photonic mode via Zeno effect. Such effect is then used to control the
stimulated four-wave mixing process and realize a suppression ratio of $34.5$.
