Or search: rag, vex, fret, fuss, rile, nark, annoy, beset, chafe, chevy, devil, grate, harry, peeve, rouse
2 Syllables: SU
broadening, jostling, modeling, offering, quarreling, softening
3 Syllables: SUU
auditing, blossoming, fostering, gossiping, honoring, honouring, modelling, profiting, promising, prospering, slaughtering, tottering, vomiting, watering

Found 20 words across 2 groupings. Skipped 1 excess word of a similar stem.