It is an linguistic inversion to give stronger impression to the listener. The general statement of your sentence would be "우리 자주 봐요." However, by saying the subject of the sentence at the end, it gave an impressive feeling. Here are more examples of inversion. e.g. '보고 싶어요, 붉은 산이.' '알 수 없어요 내 마음을' Hope it helps!