"I just really hear God telling me to break up with you"

Oh, to equip the men of Wheaton with this interpretation of the Third Commandment.

Here's the gist of it: The Third Commandment does not mean that saying the word "God" in all but a worshipful manner is sinful. Though this is probably not a good practice, the commandment is probably talking about something else: using the name of God as a source of authority in what you are saying when in fact, God has not given that word or authority.

So, to say to someone, "God is telling me to break up with you," when in fact, God has not directly told you such a thing, is a violation of the third commandment.

Now, obviously as one become more sanctified, the idea of "Love God and do what you want," as said Augustine, becomes more pertinent. So, if the time comes in a non-marriage relationship with another person that it becomes undesirable to remain in the relationship for reasons rooted in Scripture, or perhaps the trajectories of your lives are headed different ways, then take responsibility for that. Say, "I don't wish to stay in this relationship because _____."

Don't use the "God card".