Math is not easily understood by many. Take this for example:
Adding and multiplying combinations of positives and negatives is quite confusing. Care needs to be taken while dealing with them. Two pluses make a plus, two minuses make a plus but a plus and a minus make a minus.
Relating this formula to emotions when we are dealing with two people it is better that we have plus emotions of both but never a plus and a minus as that will lead to a minus. A minus is a disturbing situation.
Moral of the story – dislike both or like both. The choice is yours.
As an outsider would you avoid a situation where you like one but not the other?