Occasional run-ins with your wife [or partner] is a natural occurrence.
Well, as both of you are sleep-deprived adults, getting cranky is natural. If you haven’t had an argument during your pre-baby days, just ready yourself.
Last thing, put in mind that losing battles do not make you half a man.
You may have come into parenthood armed with the “never give in even when they cry out” mentality. But then, having an actual baby in the house means you’re going to lose on that one countless times as you’ll be finding yourself on the couch at 3 AM with the crying baby in hand trying to put him/her to sleep or feeding him/her for the nth time.
First-time and expecting, fathers, this doesn’t make you less of the man you were. You’re more as in the eyes of your children, doing these things and many others in the course of their lifetime make you their loving superdads.