Catholic moral teaching on sexual intimacy is clear – it has twin purposes, union and procreation, and is meant to unite a man and woman in love and to allow them to be co-creators with God if they are blessed with the gift of a child. This means that sexual intercourse is reserved to married couples. But as anyone who has navigated the graced and confusing world of dating in the 21st century knows, real relationships are not always clear, and the beautiful gift of human sexuality extends far beyond any specific expression such as intercourse. Thus many couples find themselves asking some version of your question: Can we do X, but not Y? How about Y, but not X? How far is too far?
One principle that flows from Catholic teaching on sex is that a couple’s physical intimacy should never exceed their emotional and spiritual intimacy. Until or unless you and your boyfriend commit your full selves to each other in marriage, you have not given your hearts and souls to each other in a way that allows you to fully give your bodies to each other. Without that deeper commitment, it’s easy to deceive yourselves about what your sexual expressions really mean. And too much sexual expression can easily cloud your discernment about your relationship, making it difficult to see where God is really leading the two of you. Doing “everything but” can be like driving a car too close to the edge of a cliff. The closer you are to the edge, the more likely it is that you will slip and fall. At the same time, you spend energy worrying about falling, rather than enjoying the view – in this case, rather than nurturing chaste expressions of care that can allow the two of you to truly deepen your relationship. It can keep you from developing the maturity that may someday allow for the commitment of marriage and all of the beautiful expressions that come along with it.
That doesn’t mean that you have to spend all your time on opposite corners of the couch. But you and your boyfriend have to do the moral heavy lifting here. Does your level of physical intimacy correspond to the level of emotional and spiritual intimacy that the two of you have? Do your physical expressions honestly convey the commitment that the two of you have for each other, or do they falsely give the appearance of a commitment that does not exist? Worse still, do those physical expressions stem not from love for the other, but from mere desire for sexual pleasure? What do you really want, for yourselves and for your relationship, and what will help you to get there? I can’t answer those questions for you. But I can suggest that the doubt you are feeling is probably a sign that greater restraint is called for.