get into trouble with this whole poly marriage.
Sure....but I would suggest you use the literal and precise biblical terms and not the Roman/State/Church terms. The term "marriage" is basically a copyrighted term or legally established term (created in the old to middle English era by the Roman-State Church) when used in its precise form. The precise biblical term is some type of union, relationship, covenant union, etc. Read over this article about the private sphere of relationships and see if this makes sense:
viewtopic.php?f=17&t=3011
Terms like "my man" and "my woman" or my "women or ladies" is the more biblical route (a return to a two word system), and it too respects the current legal systems and does not challenge them which could be seen as disrespect if we accept the idea they have the right to create a term, system, and then govern over it. There is a link forthcoming here as a resource on this. It was used as a biblical lecture at the July 4th retreat to discuss the history of the marriage system versus the biblical system of personal private unions and there is a difference. Any legal entity or person has the right to create a term and then to set the definition to it. In fact if you wanted to you could create a term, define it, go get a copyright for it, and then if someone used your term you could take legal action for copyright abuse. Basically in a sense that is the issue over using a public government term to what you really mean is a private biblical union. Getting those terms mixed up is or can be somewhat problematic at least for the moment in the culture. Legally people can cohabitate in the Lord by his Word and be in line both with the Lord and the government. But the issue of technical concern arises when you use public terms that were created and now still governed by the government.
You rightly mention the word trouble and as believers we are called to respect government and make honest attempts to follow the laws if at all possible. In this case it is really easy to do and it fits under the current Supreme Court Case Law that people can cohabitate together and do so legally in private consensual adult relations. The Bible supports the private relational approach as that was both the biblical and legal system in the 1st century church and thus using that system is not only safer but it is also most precise in its return to the ancient system instead of using modern systems.