@matrix Well if you actually follow the post Vatican II Catholic doctrine, particularly according to the theology of the body as per John Paul II, a lot of things are permitted, as long as you are honoring your wife and keeping it orderly.
A lot of Catholics are not even aware that hand or mouth stimulation is allowed as long as the seed is not wasted in a disordered manner and only ends up in its righteous place.
It might pertinent to confirm that anal practices are always a heresy though.