You pay the tax on any net profit, even if you didn't withdraw it from the LLC's account. It's still your profit from the rental arrangement.
You may be able to file a Schedule E for the rental, I'm not clear on this. Most partnerships (which includes multi-member LLCs) file a form 1065 partnership return, but there may be an exception for residential rental LLCs. Another expert will have to confirm that. But either way, any profit is taxable to the owners even if you don't withdraw it.
