fraternity sorority pair ups?

KD and KA, not Phi Mu and KA. Phi mus are everywhere and not stuck with one fraternity. You'll see them at SAE, Sigma Nu, KA, and Theta Chi as well as a few others from time to time

the groups. I see girls from each sorority at many of the fraternity parties and such. There's really not a system that puts only one group with another any more. There may be more of one sorority than another, but by and large, you'll see all the ladies at any house at any one time.

There's always some exceptions but I've typically noticed it like this from my experiences at formals and parties. Not so much pairings but who hangs with who

KA, Sigma Nu, SAE, and Fiji are all the same - Phi Mu, KD, AGD
Theta chi - Zeta, Pi Phis, few others here and there
Beta and Lambda Chi - AGD, Sigma Kappas, few others like ADPi, some Phi Mus but not as many as KA and them
Sigma Pi - AOPi, Sigma Kappas, Tri Delts usually a little bit of everything from Phi Mus and Alpha Gams to AZDs
ATO - solid mix. ADPis, Sigma Kappas, some others
Sig Ep - AZD, DZ, Gamma Phis
Pi Kappa Phi - Don't think I've ever seen a girl at their house that wasn't a Gamma Phi, maybe some Sigma Kappas too

Haven't been around others enough to know