Communication about visiting GF/spouse/family can actually facilitate things with immigration in many places. Passport and place being visited matters. And how responses are worded matters.

Saying that you are "visiting X (person) for the Y period (weekend, week, month)" can help, especially if the answers to a follow-up question gel with what a couple/relatives on vacation may do AND if there is an onward ticket that can be produced to substantiate the pax claim.