I think there’s an elephant in the room that you’re ignoring: From what you wrote to me, this guy has never even asked you out on a date. 😯
Since you’re a single mother, you really have to be careful about your dating life. Your kids have to come first, and any relationship you get into has to be a good one not just for you, but for your family. You don’t want to start bringing guys into your life who aren’t good candidates for you, and it sounds like this guy is pretty confused about his feelings for your sister. It probably wasn’t a great idea for you to be his counsel on their relationship, and from what you wrote, it sounds like you’re just falling for Mr. Right Now.
My advice is to let go and see if he works out his feelings for your sister. She may not be that into him, but he is clearly into her. Her rejection has him confused. Let him be. He’ll figure out his feelings and if he wants to ask you out after he’s completely gotten over her rejection, and he sees you as the woman who is the grand prize for him, and you think he’s Mr. Right, then and only then, is it okay to date him. But right now, it really feels like a default situation and that isn’t the right thing for a single mother.
I hope that helps. Please let me know how things go. And follow me @AskAprilcom on Twitter and on Facebook at this link: [url][/url].