Feeling More Like a Parent Than a Partner

So that night I did what I always do when I have a problem...I talked about it with my mom. I told her the whole story about how I found the pot in his room and I expected her to be horrified by it. She didn't even seem fazed by it. She even began to take his side by saying that he has been going through a lot lately and saying that I can be a controlling boy friend. What the fuck?!? This is my mother! She's suppose to be on my side! Am I really that controlling? I'm sorry that I don't want a cheating, pot smoking, college drop out for a boy friend. She tried telling me that I have to trust him and trust that he wants to be there for me, and to be there to support him and not be another enemy. She also tried explaining to me that although it's not smart that he's smoking pot, it's also not as terrible as it could be. She always did, and still does have a vision in her head that me and Mr. Myspace are going to get married and have amazing jobs with kids and pets, and blah blah blah. But I don't know if I can see that happening with out me "controlling" him. I feel the need to control him to help get him back on track. But it's so draining. It seems that if I keep getting on his case about helping his mom, getting a job, going back to school, that he eventually takes the steps he needs to, but it's just so draining. I end up feeling more like a parent than a partner. That shouldn't have to be my responsibility. But when his parents look at me asking me to talk to him what am I suppose to do? Stay out of it? I had to start telling myself that I'm the partner not the parent. I explained this to him and he was excited to hear. But I knew it was going to be hard for me to keep my big mouth shut. I went to his house and once again he was home alone. I texted him when I pulled up to the house and he replied that the door was open and to just walk in. As I walked in I hear him in the shower. I sat on his bed and kicked off my shoes. I didn't even have the urge to go through his stuff. I sat and waited until I heard the water turn off. He walked in to the bedroom with a towel around his waist, his hair was still dripping wet. He walked towards his closet. I got up from his bed slowly and quietly. I snook up from behind him and ripped his towel off. He pressed his body up against mine. His wet body seeped through my clothes. We began to make out as I put my fingers through his wet hair and gave it a pull. He threw me onto his bed tearing my jeans off of me as I took my shirt off. He pushed my legs back so that my feet were near my face. He began to thrust into me and and began to moan. Before I knew it we were laying in his bed relaxing. I could totally use a nap. I turned over on my side wanting him to hold me, but nothing. Instead he got up and went into his drawer for a pair of underwear. When he opened his draw I seen noticed huge bottle of Vodka empty. I curiously asked "oo! whats that" He giggled and told me about a party he went to with his friend and for the first time snorted coke. I just replied "oh nice". It was killing me not to lecture him about how dangerous and irresponsible he was being, but I didn't. I kept telling myself partner not parent, partner not parent, partner not parent. And everything went smoothly.I was glad that he felt comfortable enough to share the story with me, but deep down I wasn't glad he did it. I reassured myself that it's his life he's playing around with, not mine...