[quote=FelixBlue] Is it a sin for a husband and wife to, as one priest so described it many years ago, “mutually masturbate”? That is, is it a sin for a husband and a wife (who have four children) to bring each other to an orgasm without the man entering the woman?
It is a disordered act, and if done with full knowledge and free will it is a sin.
[quote=FelixBlue] If it is a sin, is it a mortal sin?
It is grave matter. Culpability and sinfulness depend upon the knowledge and free will of the person committing the act.
[quote=FelixBlue] If it is a mortal (or venial) sin, do the husband and wife place themselves in an occasion of sin when they have decided to “space their children”, and yet sleep together, knowing they may not “engage”? Should the husband sleep on the floor?
No, there is no sin in sleeping in the same bed as your spouse if you are not engaging in intercourse.