You met someone, fell for them, asked them to date you and they said no (for whatever reason). Then few months later they come back and now they want to date you. Let's assume you are still attracted to them.
Basically the reason they rejected you in the first place was because they weren't into you back then. Not because they were in a relationship/dating or something like that.
hm, well... in the scenario you're talking about... i guess i would accept him, but i would wanna know why, because he could easily just be wanting me because he has no other options, and i think that would hurt.
Definitely not, m. The person probably rejected you the first time because they had someone else they liked more than you, then after things fell apart with them, they came crawling back for any bit of attention they can get because they know you were interested in them once, but I wouldn't want to be a second option, so I'd tell her to beat it.