The key is too mask the true amount of what you purchase so it does not look as bad as it really is and although it sounds dishonest it keeps the comments and the bickering down to a minimum. You have to eliminate as much of the paper trail as possible.
Ways to do this is to either have a separate credit card with paperless billing or a reloadbale credit card or do more splits with guys so you can send funds via PooPal or Money Order for your end. You know, that's what I've heard on how to be a sneaky cigar buying bastage.