You should eat how much you need in order to recover and progress. I know that's not a great answer. If you want real numbers, I'd suggest finding a macro calculator and working out your TDEE, etc. and adjusting for a plan to "bulk." Those are useful for identifying a starting point, then to bulk up you add calories and to cut you remove calories. However, I don't know that using a formula is superior to asking the first three questions when your lifts start to stall.
If the milk is making you fluffy try eating more ground chuck or sirloin. Just promise her you'll "do a cut" when your squat gets over 500.
For what it's worth, when I ran NLP I went from ~230lbs to ~280lbs at a height of 6'4" and 36 years old. I think I added an inch, maybe 2 to my waist. My wife didn't mind, and my sister wondered where I had put it. One of these day's I'll try to shed some of the belly fat. Maybe when my squat gets over 500.