Love is not only about happiness. It s Disney way of looking on love. Sometimes love is very painful, but it's still love couse you care so much about someone and nobody touch some part of you, that you don t even know that you have.
Love is more about how important is someone for you and what someone make you feel. Between Ian and Tj is love, they are very important for each other. Even if Ian will end with Jo, he never will feel something so deep and strong like he feel towards Tj.
Love is not about being happy, but about what you feel to someone.