Just to elaborate on what the loan officer probably didn’t explain well enough.

The reason they won’t do a loan is because of your boyfriend. When two people apply for a loan, the bank heavily weighs their decision on the person of “lesser means” because of the “breadwinner” loses their job or can’t work anymore then the responsibility falls to the other co-signer. This includes that persons credit score. So even if you have a perfect credit score, if you apply for a loan with a person with a score of 400, the bank will ignore yours and focus on the lower one.

Banking isn’t too difficult to explain but it’s often overlooked in school. “I’m a bank” and “you’re a loan(mortgage) applicant”. You come to me asking to borrow my money to buy a house. Well I’m not going to give it to you for nothing, I’m going to attach some strings to it to make it worth my time (interest). And before I give you the money I need to consider “Is this person actually going to pay me back? Or are they going to run away with it or go bankrupt and lose my money I gave them?” That’s the reason why banks look at the person of lesser means, because if you have the better finances and suddenly get hit by a bus, now everything is on the other person and may not be able to keep up with repaying the loan.

Now what you can do, and this is risky from a personal standpoint; is you apply by yourself and your boyfriend just continues to feed money into your bank account. Basically remove your boyfriend from the bank’s calculation on “if they’ll get their money back”. It is a great risk because your boyfriend will develop zero equity in the house but you have the option to add them to the mortgage or deed later on. (Don’t do the mortgage until they’ve developed their credit, and financial stability, otherwise you just end up in the same position in the bank’s eyes)