~ee words

There are many words ending in ‘ee’, and are mostly pronouns. Some of these have an opposite, ending with ‘er’ or ‘or’, such as:
interviewee – interviewer
employee – employer
trainee – trainer
examinee – examiner
nominee – nominator (notice a small change)
referee – referrer
abductee – abductor
payee – payer

Other words have no opposite, such as:
absentee
divorcee
evacuee
refugee
addressee