I have had 3 babies...and teared all 3 times now.

#1 was due to a vac extraction and she came flying out (2nd degree tear)
#2 was a small tear, not sure why but im assuming due to birthing on my back (1st degree tear)
#3 was due to DS pushing hard on my waters and me birthing upright, once the waters broke he crowned straight away...waters was all that was stopping him from 'falling out'. (2nd degree tear)