Two people sit and trade stories about what has made them happy, what has made them feel worthless, and what has made them cry. It starts as an ordinary, honest conversation. The other person remarks that the speaker must cry a lot, and the speaker simply agrees, writing it off as being sensitive. It seems like a small, gentle moment.
The last two lines change everything. As the talk goes on, the speaker realizes that this same person will one day be the reason for those tears, every night. The poem doesn't say how or why, which makes the line feel more like a quiet premonition than an accusation. The speaker's feelings are a mix of openness and dread: they have just shared their vulnerability, and they sense it may be used against them, or simply that they will be hurt. The mood begins warm and intimate, then turns bleak and uneasy, leaving a sad sense of knowing too much, too soon.