Is this a red flag?

I know I’m Going to get the “it’s his money not your business” comments. But I really feel like I should be concerned about his money handling because I want to marry my bf. I think how someone manages their finances can determine potential in a marriage 🤷🏻‍♀️ but idk if I’m over looking at this

So a month ago my bf told me he had about 5k in his bank. He’s self employed

He’s under my cellphone bill so he pays me 20 bucks only. We got a deal that’s why

So the bill was due and last month he told me “can I just give you cash” I said yeah!! He only gave me 15 cause he was missing a 5 dollar bill. I wasn’t mad or anything it’s just 5 bucks

But then today he forgot to pay me this month and I didn’t want to mention it. We go out to get some burgers to eat and he pays with his card and says “idk if there is enough money”

The meal was 22 bucks. I offered but his card did he go through. I’m questioning where all his money Goes.

He lives with parents

Then today he brings up the topic how dirty business brings more money … I was confused and he said “drug smuggling “ I told him to not consider that and he said “I won’t baby I just have friends in that business and they make alot”

😒😒😒 he was making tons of money suddenly and now he told me and he wasn’t sure if he had 20 bucks in his account?