"What people call "love" it's just a chemical reaction that compels animals to breed. It hits hard, then it slowly fades, leaving you stranded in a failing marriage. I did it, your parents are gonna do it, break the cycle Morty, focus on science."
The harsh reality of life is that all relationships are necessarily about value transference. If we're not stronger together than we are apart, then what the hell are we doing together. If you're sucking more value out of me than you're giving back, then you're a parasite and I'd be better off without you.
If you're not doing the calculation of whether a relationship is and will continue to be mutually beneficial, you're almost certainly going to become a host for a parasite.