I thought it was a fairy-tale.  True love.  It just happened.  She was my best friend become girlfriend (and eventually spouse, and then eventually ex).  Fumbling hormonal fueled kissing and rubbing.  A slip and it was done.  It was amazing and opened a flood gate of complicated emotional responses in the after-glow.  I was floating on a cloud for the next few days, and randomly crying out of fear of pregnancy.  We were both young.  Too young to have children.  Stories and sex-ed can never prepare you for the emotional side.