nothing to worry aabout ...this is normal
Hi U, It means you yave a very sext g/f if she can do this to by just talikng to you, its ok your just a normal healthy young man, perhaps highly sexed, surrgest you were a condom when,talking to her.
But in the mean time, try doing some kegels, iots a simple exercise to strenthen up you pc muscle, for these just google pegym and look under exercises.
Good Luck