Q. How should we respond to our daughter who wants to bring her girlfriend for Christmas to our home? She knows we love her and that we do not condemn her for being lesbian, but we do not approve of her sexual activities. — Name withheld

A. Addressing the problem of homosexual acts, St. Thomas Aquinas writes in Summa Contra Gentiles:

We have said that God exercises care over every person on the basis of what is good for him. Now, it is good for each person to attain his end, whereas it is bad for him to swerve away from his proper end. Now, this should be considered applicable to the parts, just as to the whole being; for instance, each and every one of his acts, should attain the proper end.

The proper end of sexual acts is the realization of the good of marriage, a relationship defined by bodily communion and procreativity. All complete sexual acts, therefore, should themselves constitute the couple as a one-flesh unity and should remain open to procreation (even if they are not factually fertile). 

If any sexual act is by nature non-unitive or non-procreative, i.e., it is not the kind of act through which procreation could be pursued, then that act fails to attain its end and so is unreasonable and wrongful. Homosexual acts do not constitute the participants as a one-flesh unity, and they are intrinsically sterile.

It’s important to keep in mind Aquinas’ maxim when addressing this difficult issue. Conforming our behavior to the moral norm against homosexual activity is good for us. Violating it is bad for us.

During the Obama administration, and especially with the 2015 Obergefell v. Hodges decision, a homosexualization of U.S. culture has taken place. A kind of “homomania” has overtaken much of public life and especially the entertainment industry. The mindset brooks no dissent. It demands acceptance. Anyone who opposes it suffers epithets such as “hater” or “denier of marriage equality” and the like.

It’s especially difficult when the issue divides families. You rightly feel anguish at the prospect of limiting your daughter’s visits. But the reasons are of paramount importance. When good people, especially committed Catholics, fail to take a stand, they can appear to accept the homosexual lifestyle. This makes this kind of wrongdoing seem more acceptable, provides material for rationalization and self-deception, tempts the weak and confuses the doubtful or ignorant. The spiritual health of your daughter, and of the souls of other family members and friends, is what you rightly concern yourself with when addressing this decision.

Although homosexual inclinations may be involuntary, homosexual activity is always grave matter because it can be neither unitive nor procreative. Not only must we avoid engaging in such acts, we should avoid supporting or even coming across as supporting them. So your question concerns proper boundaries so as not to come across as supporting your daughter’s lifestyle.

A boundary line should be drawn at overnights: no sleeping in your home. While not intrinsically evil, it would give a very confusing example and could scandalize people to believe that you are morally tolerating homosexuality.

As for day visits, you could draw boundaries in different places depending on your circumstances. You could ask your daughter not to bring her partner home for Christmas, i.e., you could draw the boundary at visits. If you have other children at home, there is a greater urgency not to appear to support the lifestyle. I would say that if your daughter has younger siblings at home, siblings who are vulnerable to her influence, then you probably shouldn’t welcome the woman into your home. And make the reasons clear when you speak with all your children. 

But if she has no siblings at home, you might consider welcoming them both. In doing so you would be materially cooperating in their wrongful lifestyle. I materially cooperate with another’s evildoing when I perform an act that contributes in some way to the success of the other’s wrongdoing, but when my act does not agree in the wrongdoer’s bad intending of the wrongful act. I do not will that the evil be done, but I contribute to the evildoing in some other way. Welcoming the couple into your home, despite your convictions, supports them as a couple. You do not intend this, but rather tolerate it as an unwanted side-effect of your proper intention to express Christian charity to your daughter. 

This type of cooperation would not be licit if it caused scandal, that is, if it led anyone to sin by the example it gave. It also would be wrongful if it compromised your witness to Christ and the good. If in cooperating your ability to bear witness to true marriage and chastity was undermined, then it would be wrongful. So you would need to ask yourself whether welcoming them into your home might do one of these things. If you do not think others will pay much attention to your cooperation, regard it as significant and draw practical conclusions from it, then it could be licit. 

Either way, you should use the occasion to witness by your life and words to the goods of marriage, family, and chastity. 

Finally, always avoid harshness. Be gentle in your communications and patient in your replies. At the same time, don’t be tempted to think that drawing firm boundaries such as these is uncharitable, that somehow it is unmerciful. Any notion of mercy that tolerates acts that place one’s soul in jeopardy is spurious.