<p>In my freshman year quite a few people came in having a significant other, and all of them broke up. Maybe the number was around 10. </p>
<p>I did meet a girl in my class, and her and her significant other were on opposite sides of the country for a year or two, and are still together. They did visit one another though.</p>
<p>So I would say not very often, but it is likely. I would say near impossible when its nothing more than a crush though.</p>