  In this paper we prove sharp $L^\infty$-$L^\infty$-$L^\infty$ decay for
certain trilinear oscillatory integral forms of convolution type on $\mathbb
R^2$. These estimates imply earlier $L^2$-$L^2$-$L^2$ results obtained by the
second author as well as corresponding sharp, stable sublevel set estimates of
the form studied by Christ and Christ, Li, Tao, and Thiele. New connections to
the multilinear results of Phong, Stein, and Sturm are also considered.
