Should I stay?

Alright, I just started dating a guy I've known since I was small. We've been best friends since but stopped talking for a year when I got with an overprotective boyfriend. We recently broke up and now I am with M, the man I am dating now. Now, we've been dating for almost a month (really short, im aware). I'm not sure if I'm starting to notice red flags or not.

First off, M acts as if we're just friends in school. He walks up to me barely and says hi or something and walks away. We've never held hands or said anything romantic, we've never been on a true date. Yet, we've kissed, made out, and he's grabbed my boob (I did not volunteer) more times than he's texted back. Its weird to me and I feel as if I'm an object to him and he's dating me for benefits. Part of it is we're both shy and awkward but it's still weird to me. He also asks my friends if I'm mad at him instead of me. I also feel as if I can't be myself around him which hasn't happened before in the beginning of my old relationships. My ex talks trash about me to him and he doesn't defend me either. I know he likes me and all that but I don't know if it's right.