Why? Why?

Last night we argued. He always say he was tired after work. Each time, when i ask him out after his work , he will give me excuse like tired, lazy, body ache and bla bla bla. But when his friends ask him out he never came out with all this excuses. Last night he was back home, and his friend ask him to go out drinking. That time was already 10 something. I told him not go, cos he already so tired after work but he insist. He said he had to entertain this friend cos this friend help him before. I told him if he went out with his friends then don't call me or find me anymore. He jus ignore wat i said...and he went. I know he will ignore me and let me mad at him and he will try to persuade me the next day. And he also know i will forget about the arguments the next day, and i will forgive him. I told myself not to give in so easily but............ He already called just now.........and i already forgive him...... Why ar? This love thing so complicated...........