**Yes, it could be a problem—but denial is not automatic.** Visiting a boyfriend or girlfriend is generally a permitted B‑2 purpose, provided the visit is temporary. CBP still decides whether to admit her; a visa does not guarantee entry. [State Department guidance](https://travel.state.gov/content/travel/en/us-visas/tourism-visit/visitor.html)

The key distinction is what was true **at the visa interview**:

- **If you started dating afterward**, the two answers can both be truthful. She should explain the actual timeline if asked.
- **If you were already dating and she knowingly denied it**, that could raise a misrepresentation issue. The legal standard requires a *willful, material* false statement—not every inaccurate answer qualifies. A statement can be material if it blocks questions relevant to visa eligibility. In your situation, concealing the relationship could potentially affect the officer’s assessment of whether she intended to return home. [Official State Department standards](https://fam.state.gov/FAM/09FAM/09FAM030209.html)

A finding of material misrepresentation can cause **permanent inadmissibility**, although waivers are available in some circumstances. Being truthful at the border does not automatically erase an earlier material lie. [State Department explanation](https://travel.state.gov/content/travel/en/us-visas/visa-information-resources/visa-denials.html)

She should answer CBP truthfully. If she deliberately denied an existing relationship, she should consult a U.S. immigration attorney **before traveling**, giving them the exact interview question, her answer, and the relationship timeline.

Were you already dating when she had the visa interview?