Sometimes, after she's put into Pet's body, she catches Ian looking at Melanie. Melanie seems to think that she should have a problem with it, but she doesn't - not really. She finds herself with the same impulse sometimes, and finds her eyes drawn to Jared before she remembers to look away.
Because it was Melanie's feelings but she remembers how it felt to love Jared.
And it was Wanda inside but Melanie's body, even if that was neither of their fault.
But she can't hate Ian for it because she understands. Most of the time they are a couple but sometimes it's a square.