@strivingforgodsglory Here's something you can do - ask him to get a credit-checking service and show you his credit score, and to drill into the active accounts he has.
If he has a perfect 999 on Experian and has never set a foot wrong, then it may just be a good idea.
However, that report will say whether he's current on any credit he has, whether he's been paying his bills on time, and a whole bunch of other useful things.
If there are any monsters lurking under his stairs, that will quickly tease them out.
If he refuses to let you look, it's an absolutely safe bet he's hiding something - letting someone see your credit report is absolutely right and reasonable if you're currently trying to get them to buy a house with you.