I was introduced to S-Expressions a few decades ago yet it is still the case that 100% of the time I pronounce 'SEXP' as 'SEX-P'

Ah the traditional lispish naming for predicate functions, applied to questions of an amorous nature!

I occasionally run across something called K8-Sexecutor, or at least that's how I pronounce it.

the children's exchange dot com drops the s, just in case.