The question is unclear, is there more to it?
I cannot answer this question without knowing the circumstances, but it is good to remember that mutualism is where both species and/or participants benefit, and parasitism is where one species benefits and the other one is harmed.
Think of mutualism like the word mutual, so when people say " the feeling is mutual" it means that both parties feel and/or express the same feelings. Parasitism should be thought of like a parasite. When one is infected or has contracted a parasite, the parasite will live off of its host body making it ill or even causing death as it drains resources from its host to benefit itself.
