Upset him
The clause, In order not to upset nearby neighbors, does not need any apostrophe.The neighbors' pool looked inviting.
they both mean the same thing.
That is the correct spelling of "upset" (disturbed, or to disturb or spoil, e.g. upset his plans).
Uncertainty, uneasiness, unhappy and upset are emotions that begin with the letter u.
The correct spelling is disgruntled (unhappy, upset).
That is the correct spelling of "distraught" (upset, distressed).
· uncertainty · uneasiness · unhappy · upset
the letter upset him: his ex-girlfriend sent his letter back unopened.
That is the correct spelling of "perturb" (to upset or imbalance).
That is the correct spelling of the verb "to disturb" (to bother or upset).
That is the correct spelling of "disruptive" (causing upset or disturbance).
No. "Upsetted" is not a proper usage of the word "upset." If you need to say something made you upset in past tense, saying "upset" is still the correct form of usage.