I don't know what to do anymore... my mom doesn't like the fact that my boyfriend smokes and well I don't mind it... I actually smoke as well... I just don't feel like she should judge who I am with...

Well there are allot worse things y'all could be doing.
While not good for you allot of people smoke, it's not poison gas (well not exactly) and it is legal.

Does your mom know that you smoke too?

If he treats you well, respects you, loves you, and is a nice guy. Smoking shouldn't matter. :) And your mom should see that.

Your mom may not like something in a guy you date... and she has right to her opinion... she is looking out for you... let her know that you hear her, you understand her concern, but it is not that big of a deal for you right now. Does she know you smoke?

Your mom just loves you and prob. Don't want you to get hurt. Smoking is legal if your 18 but it is harmful to your healt. But as long as your boyfriend treats you with respect and you don't mind then I don't see the problem.