I found out that this guy- we're going to call him Adam- liked me around a year ago, when his friend told me. I didn't think it was true, until I started paying attention to his behaviour around me. He had asked me to hang out with him several times, but I wasn't that close to him and had been very busy so didn't go. However, I then started dating this other guy and, as soon as Adam found out, he kept asking about my new relationship. Around two weeks after I started dating this guy, Adam stopped talking to me. Then, as soon as we broke up, Adam went back to trying to ask me if we could hang out, but I was travelling at the time so couldn't. I didn't think much more of it until a few months ago. Adam asked me out and, after I explained that I didn't feel the same way, Adam avoided me for around a month. I thought he understood, but, after that month, it only got worse. He continued to flirt with me, passed comments about "my beauty and voice", stared at me constantly, and always came as close as possible to me in a large room filled with people. I would just turn around, and he'd be standing less than three inches away. I felt very uncomfortable. I try to move away from him and not pay attention to him, but it never works. It's important to note that Adam has a mental illness, so I felt like I could never confront him about how uncomfortable he made me, because I'd just end up hurting him. This has been going on for months now, and I just found out that he has bought me flowers and a golden rose for Valentines day. How do I get him to understand that when I've said no, I really mean it?