He should get his own bank account.
If his name is not on the account any tax refund received as a direct deposit will be rejected by the bank. The bank will send the refund back to the IRS and/or State. The IRS and/or State will then mail the refund as a check to the address on the tax return.
NO. If he tries to use a bank account that does not have his name on it, the bank will reject the deposit and send it back to the IRS. Then the IRS will mail a check to the address on his tax return. Maybe your BF ought to open a bank account of his own. It's not that hard to do.
https://ttlc.intuit.com/questions/1901159-can-i-deposit-my-tax-refund-into-someone-else-s-account
Here is what the IRS says about entering incorrect banking information