"So I'm a convenient person." She doesn't sound annoyed, because isn't. He seems to lack emotion and probably would be honest if he intended to do anything weird. Of course, telling him doesn't mean trusting him. It means only that she doesn't feel threatened by this.

"...I do serve someone but willingly. He's a friend. Actually, I've made a few friends. Weird..." That part is more to herself, but she shakes her head and continues. "It was...hard at first. But at this point, there's someone I care about enough that I want to have a future with him. So I guess that answers it."