Rules of expletive infixation

Expletive infixation refers to inserting expletive or euphemism into a word for emphasis. The rules are as follows:

1. No infix within a syllable
2. Depending on the speaker, an infix either
   1. May come before any stress
   2. Must or preferable come before a primary stress only
   3. Must come between stresses
3. Infix comes between (but not within) a foot

A trochaic foot is a pair of syllables where the 1st is stressed and 2nd is unstressed.