Boyfriend smokes, some advice please? Options

[*iNyCxShoRT*]

Recently I just found out that my boyfriend smokes [since last month]. It kind of disappointed me, but I was willing to support him whatever he decided to do. He told me that he didn't want me to hurt so he said he would stop. He promised me he would. About two days passed and he admitted that he had smoked the day before. He apologized and repromised that this time was for real and he wouldn't do it again. Things were going great for a good 2 weeks. But today, we got into a little arguement because our plans were a little roughed up and he got upset. I tried talking to him but he only walked away, supposively "off to the park, i don't want to hang out with you guys". So I tried my best to have a good time until I finally got to talk to him when I got home. As I was walking home I ran into my friend [whos a highschool bad boy] when he saw me, he was like "Wait!" he told me that my boyfriend was smoking today, [smoking with the highschool bad boy as a matter of fact]. While this was all happening he said that he asked my boyfriend if I approved of this, and my boyfriend just hesitated and went. "Oh...we got into a fight." This disappointed me bacause he promised me he would quit. But he may have been under stress. Should I talk to him about it...or give him another chance, I don't know what to do.

[think; 13 yearold kid]