pay-to-play DMs as a single woman... how do you stay polite about it

i need a vent and also some practical wisdom. solo woman in vancouver mid thirties been in the scene a while. about once a fortnight some man slides into the dms offering money for a night with him and his wife. half the time the wife doesn't even exist on the profile. i'm not a sex worker and i've nothing against people who are, but the assumption that as a single F in LS i must be available for cash is exhausting and a bit insulting. how are people responding to these without either blowing up or going passive aggressive...