This by way of Ryan, a former student of mine, currently dating a lovely Russian girl:

Learning a foreign language is difficult. Sometimes it is downright dangerous; like when you accidentally tell your girlfriend that she has a great mustache when you meant to compliment her lips. The difference between губы and усы is noted...

Such little misunderstandings are very common in cross-cultural relationships. Back in 1991 I was dating a woman who had been the national shot-putting champion of Albania. We were in Paris at Cafe Vesuvio not far from Rue de Leningrad, sipping a local red wine whose name I have forgotten, when she looked at me with moist eyes and said, “You have the most beautiful uterus.” Not wanting to spoil the mood, I replied, “Thank you, mon petit chou, my uterus is yours and only yours.” She was visibly moved; no man had ever said such a thing to her before, though doubtless many have since. Alas, our relationship did not last the weekend, and I am left with only misty, water-colored memories...

The Russian word for lip is губа; note the shifting stress in the plural:

The Большой толковый словарь at gramota.ru defines губа like this:

That is about as unromantic a definition as you can find. On a more human level...