I moved in with my romantic partner nine months ago. My partner owns 100% of the property and pay about $1000 per month to the mortgage (minimum is something like $300). Partner had no intention of renting any part of the property out, but we both wanted to move in together as our relationship progressed. We worked out an agreement where I pay $500/mo in "rent" to support my partner, as I didn't want to take advantage of the situation by staying free.
What should we be aware of in terms of the tax implications of such an arrangement? In particular, I am interested if this "rent" payment which is sort-of optional is taxable, and what our legal options are to not have this money I'm trying to support my partner with be docked 30% by the government - such as putting something in writing, or some form of co-ownership.