What about folks who simply live together for convenience? What about people who live next door, but are close friends? What about just close friends?
The problem is not who is and who is not included in the exemption; it is that there needs to be an exemption and that it only exists at the whim of government.
I won't fight for an exemption for homosexual couples. I don't give a crap about them. I will fight to keep private sales private and out of the hands of government. I will fight to end background checks for all transactions.
I will point out that this clearly demonstrates that leftists in power will step on whoever they have to in order to increase their own power--even leftists not in power. This story drips with irony.