I have no idea what his intentions are. And if anyone here says they do, they are either lying or deluded. The only person that can answer that is your ex. But I am more worried about why you are giving this person the time of day, you're worth so much more.
He cheats on you, which is very wrong. Instead of him realising he's in the wrong and begging for your forgiveness, he doesn't have to bother because you ask for him back. And he says no! Stop asking yourself the question 'what are his intentions'. This guy has had far too much from you already. Instead, ask yourself 'am I worth more'? The answer is yes! You deserve a boyfriend who does not cheat on you and, if he stupidly does make a mistake, HE asks for your forgiveness and comes back to you, not the other way round. Respect yourself more and love yourself to know that you are good enough to have a boyfriend who does not treat you like this, and then gets annoyed just because you won't be friends with him. He doesn't deserve your friendship.
The road outside your house is public property; he can sit in his car all day long outside it. Just let him! Perhaps seeing him there will make you realise how immature he is. If it goes further and he starts following you around, talk to the police (and get support from a good friend or family member). Stalking is a serious offence and no one should have to put up with it, especially from a guy who could not stay faithful to you and is having a bit of a silent tantrum just because you don't want to be friends.