here's my big brain take. (i never watched the later seasons and refuse to believe katrina had an affair with a man with a newborn baby?? or something.) katrina is a lesbian <3 and rachel is bi af. and I'm fine with mike/rachel but obbbbviously mike/harvey is THE pairing. and. listen. katrina/rachel. the few scenes they worked together they were SO GOOD. and they both love the ballet. both foodies. katrina gets on great with rachel's dad. and made rachel feel really good re: him too. AND katrina and mike's friendship is the best.
hi sweet anon this has been sitting in my inbox for MONTHS! i apologize
katrina is absolutely sapphic, though personally i headcanon her as bi. but yes omg katrina/rachel has SOOO much potential like god truly an enemies to lovers storyline!!!!!
(also btw in the later seasons she does develop feelings for a married guy but they never actually have an affair thank god)