A father is the guy who tucks the child in at night. Who is their to put the bandaid on the scraped knee. Who changes the diapers regardless of how disgusting baby-poop is. Who is up all night at Christmas putting together the toys. Who walks into the house after a hard days work and is greeted by shouts of "daddies home" and hugs. The guy who kills the icky spider in the bathroom.
Day in and day out...that is taking care of your child.
Not any 50/50 convenience where the kid gets pawned off back and forth.In 15 years, who will your kid be calling "daddy?" You, or some other guy who comes along in a few years? Or perhaps the dope dealer on the corner because he was the only male figure of importance in the kids life?
When you make a baby your life becomes fully obligated to that child. Your own wishes, desires, loves, hates, wants, and needs are secondary.