Mouth to breast intimacy before marriage is absolutely a sin. It is immoral. It is in no sense a biblically acceptable alternative to sexual intercourse for unmarried couples.
Prayer to be a faithful disciple
Is mouth to breast intimacy a sin if done before or outside of marriage?
This question is becoming increasingly common as young people are told that “ mouth to breast intimacy is not really intimacy,” and as mouth to breast intimacy is promoted as a safer (no risk of pregnancy, less risk of sexually transmitted diseases*) alternative to sexual intercourse. What does the Bible say? Ephesians 5:3 declares, “But among you there must not be even a hint of sexual immorality, or of any kind of impurity…because these are improper for God’s holy people.” The biblical definition of “immorality” is “any form of sexual contact outside of marriage” (1 Corinthians 7:2). According to the Bible, intimacy is to be reserved for marriage (Hebrews 13:4). Period. So, yes, mouth to breast intimacy is a sin if done outside of marriage.
How to love God with all your heart, soul, mind and strength
Is mouth to breast intimacy a sin if done within a marriage?
Many, perhaps most, Christian married couples have had this question. What makes it difficult is the fact that the Bible nowhere says what is allowed or disallowed sexually between a husband and wife, other than, of course, any sexual activity that involves another person (swapping, threesomes, etc.) or that involves lusting after another person (pornography). Outside of these two restrictions, the principle of “mutual consent” would seem to apply (1 Corinthians 7:5). While this text specifically deals with abstaining from sex/frequency of intimacy, “mutual consent” is a good concept to apply universally in regards to intimacy within marriage. Whatever is done, it should be fully agreed on between the husband and his wife. Neither spouse should be forced or coerced into doing something he/she is not completely comfortable with. If mouth to breast intimacy is done within the confines of marriage and in the spirit of mutual consent, there is not a biblical case for declaring it to be a sin.
In summary, mouth to breast intimacy before marriage is absolutely a sin. It is immoral. It is in no sense a biblically acceptable alternative to sexual intercourse for unmarried couples. Within the confines of marriage, mouth to breast intimacy is free from sin as long as there is mutual consent.