abstract: I will talk about random processes generated by Birkhoff sums on slowly mixing nonuniformly hyperbolic dynamical systems such as Bunimovich flowers, and about their approximation by a Brownian motion, so called Almost Sure Invariance Principle (ASIP). This is a rather special result about rather particular systems, but in a way it completes a long line of research. This is a joint work in progress with C.Cuny, J.Dedecker and F.Merlevede.