My boyfriend is asking for $500... this is a bad sign, right?

He's been asking for $500 over the past 3 days and seems persistent about the request. He's explained that this is the first and only time he asked me for money, how it's really for a family crisis and some urgency.

I'm super hesitant and told him no, which he kept replying with an ''Why? You don't trust me that I'll give it back? I will. It's only this one time. I'll pay you back $100 each month''.

I'm starting not to like this. I've never asked him nor anyone for money. He's the first person that ever asked me for money. Is this a bad sign right?

Updates
9 mo
Why is he insisting on it so much? Even though I don't have any financial crisis, $500 still seems too much to be asking a partner for.
My boyfriend is asking for $500... this is a bad sign, right?
Post Opinion