Is this cheating my gf the home nurse

I am 35 m gf is 28f both pretty fit and in shape my gf has recently taken up part time home nursing of the elderly for abit more money. She bathes them sometimes and one guy 70s sever arthritis she told me has to bathe and often gets an erection. Her boss said due to how he is she has to help clean his penis and she as recently and he quickly moaned loud and came all over himself and a little hit her. She told me as felt I should know and was shocked. Not sure if cheating as maybe part of the job right?