Disregard what your coworker is telling you. It appears he is intimidated by your efforts to ride your bike to work and doesn't like the fact that you are enjoying yourself so much. As for the child, like others mentioned, it will be a culture shock at first but life will take on that new normal real quick. Don't worry, you'll ride just as much as usual even though you may commute to work a little less at first. It really depends on how you and your wife will set up your new schedules. Evenings and weekends you can always take 1 hour rides by yourself which will be great and when your child is a little older, like 18 months or so, get one of those trailers so you can take your child along while your wife does errands or shops or whatever. Those are the safest and best way to go. Use the Local MUP or ride in low traffic residential areas. I had 3 kids, all grown now but thats what I did and it was seamless. No worries.