Whether he's your coworker, roommate, supposed friend or part of your extended social circle, his clear dislike for you is palpable. When someone hates you it is tempting to bite back. That said, being nice to someone who is making your life miserable can help break down barriers between the two of you and possibly make the situation better. This isn't to say that the two of you will become fast friends. Instead, set a goal of understanding why this person hates you and work toward being the better person.
Accept that the other person's issues may be her problem. Unless the offender has actually come up to you and said she hates you, consider the possibility that something else is causing her to act out. Take her point of view, suggests communication coach Preston Ni in his article "8 Keys to Dealing with Problem People" on the Psychology Today website. For example, ever since you got a promotion your coworker storms off in a huff when you enter the break room. Consider the possibility that she is upset because she got passed over for the promotion. Go up to her and say something such as, "I see that you're frustrated because you didn't get the promotion. I think you're doing a great job and your work should be recognized."
Speak to the hater constructively. Even though it is tempting to toss an insult back to someone who dislikes you, being nice means focusing on the positive and not the negative. For example, your friend's boyfriend snarls, "Why are you always hanging around us? We don't want you here." Instead of shouting back, "I don't want to be anywhere around you either," try something constructive that has a nice tone such as, "I understand that you want to spend alone-time with Jane. I think it's great that you want to be close to her. I can respect your needs and will make plans with her for another time."
Follow the old adage: If you don't have anything nice to say, don't say anything at all. You don't need to fight every battle. If your efforts to turn the situation around or resolve the hater's problems with you don't work out, take a step back and don't say anything. Keep your cool, smile sweetly, politely excuse yourself and don't argue.
Balance being sweet with being sappy. Going overboard with praise or compliments can have the opposite effect when dealing with someone who doesn't like you, writes licensed mental health counselor Donna M. White in her article, "Dealing with Difficult People," on the PsychCentral website. For example, your friend's sister has made it clear that she doesn't like you. Instead of constantly complimenting her in an effort to win her over, tone it down and offer praise only when it is appropriate. This may include situations such as after she gets a new job or when she shows off a new outfit.