Any person in Family Tree Maker can be assigned up to 99 spouses, so adding two shouldn't be a problem. If you don't want them recorded as husbands, click on the button to edit marriage details (its placement may vary depending on FTM edition, but on 2006 its adjacent to the marriage date/location fields). There you can change the relationship from "married" to one of several other options, or select "other" if none of them suit you. From what you've said I think "partner" may be the best option since it will show up as such on the family view screen, but some of the others don't.
If you ever research royal genealogy, particularly in China, you will sometimes encounter kings who had 100s or even thousands of concubines and in rare cases up to 1,000 or more children. That's when it can get complicated.
If you ever research royal genealogy, particularly in China, you will sometimes encounter kings who had 100s or even thousands of concubines and in rare cases up to 1,000 or more children. That's when it can get complicated.