  The deformability of a compact object induced by a perturbing tidal field is
encoded in the tidal Love numbers, which depend sensibly on the object's
internal structure. These numbers are known only for static,
spherically-symmetric objects. As a first step to compute the tidal Love
numbers of a spinning compact star, here we extend powerful perturbative
techniques to compute the exterior geometry of a spinning object distorted by
an axisymmetric tidal field to second order in the angular momentum. The spin
of the object introduces couplings between electric and magnetic deformations
and new classes of induced Love numbers emerge. For example, a spinning object
immersed in a quadrupolar, electric tidal field can acquire some induced mass,
spin, quadrupole, octupole and hexadecapole moments to second order in the
spin. The deformations are encoded in a set of inhomogeneous differential
equations which, remarkably, can be solved analytically in vacuum. We discuss
certain subtleties in defining the multipole moments of the central object,
which are due to the difficulty in separating the tidal field from the linear
response of the object in the solution. By extending the standard procedure to
identify the linear response in the static case, we prove analytically that the
Love numbers of a Kerr black hole remain zero to second order in the spin. As a
by-product, we provide the explicit form for a slowly-rotating,
tidally-deformed Kerr black hole to quadratic order in the spin, and discuss
its geodesic and geometrical properties.
