Covering for a friend who’s hurting someone isn’t loyalty. It’s joining in with better excuses.

Loyalty always points somewhere. It is meant to protect a person, and when it starts protecting what that person is doing to somebody else, it has quietly changed jobs. The excuses make this hard to see, because they are usually sincere and usually about how much your friend is going through. Meanwhile the other person is still being hurt.

Separate the two: you can stay close to someone and refuse to help the thing they are doing. Say the plain version to them once, with no audience. If it carries on, telling the truth when asked is not betraying a friend, it is only the end of a cover.