Ace, it's his job to bring up his own credit score, not yours. Seeing that you're not living together and not talking about marriage and he keeps trying to cadge presents out of you, I think it would probably be wise to change your password, keep his name off your credit cards, and maybe even have the credit card company issue you a new card with a new number. When you gave him your password, it gave him access to your credit. Seeing that he's acting so hinky and suspicious, well, I suspect him of maybe not having the best intentions in the world.

I tend to think that way whenever someone starts making a lot of unfounded accusations. Seems like they're usually talking about their own guilty thoughts and actions, and blaming (projecting) it all on the other person.

It's not a big hassle to have the credit card company issue you a new card with a new number, with his name not attached to it in any way. Then watch your statement carefully for odd charges in the next billing cycle.

He won't like it. Too darn bad. He's behaved badly and it's not your job to save his credit or assuage his angry feelings when he really is giving you a hard time you don't deserve.