Regarding my comment we of course don't know what kind of passport he holds. I find it interesting that out of so many visits you have never encountered a hostile/rude officer, specially since Miami is in your list.

I actively avoid Miami as a) its ultrasuperbusy b) 'rude immigration' or even 'rude gate agents ' are quite common although in MY personal experience they have all been professional but NOT 'pleasant'/ (which I agree, is not their 'job' , they are trying to figure out who will overstay/work/etc from the 'normal' people and that cant be easy)

In Houston/Dallas/and even EWR I've never had an issue.

For the OP, as long as you can explain why you are going twice in a short period of time and tell them where you are staying etc (all the normal stuff) I doubt they will give you any hassle specially if (as I would imagine) you hold a british passport. They can't really be rude to you if you dont 'let them'.... 'yes sir' /'no sir' / 'ty sir' is all they get from me (on the other hand when I travel with Mrs Wolfie who is American she talks/smiles/engages in small talk ........ )