Even if it's not a temptation issue, it's still inappropriate. And for that matter, not just in taking her to his home, but being alone with any woman (other than his mother, sister, etc.) for an extended period of time, period. And that's whether he is married, engaged, whatever. Further, you two should not be spending time alone together in his home either. Both for how it looks to others, and for the obvious issue of temptation. I don't say that from some high-horse position. When I was engaged, we did spend way too much time alone and constantly battled temptation. In hindsight we did not act as we should have. It's not a good way to go. Better to spend time together in public places and/or with friends and family.
Another example: a couple of years ago I had to take a long trip to attend a course, and a family friend was attending as well, so he drove us there. It was, of course on the up and up, but we both realized along the way how odd and uncomfortable it was. On the trip back he saw one of his neighbours and realized he now needed to explain to her why he was on this trip with another woman, and that was not even an "alone" situation. These things do matter, and we should be aware of them.
The music director at my church cancels practice on days when everyone calls in sick except for one of the women. He won't be alone in the building with just another woman. It's not that he's afraid he will stumble, it's just inappropriate and could start any number of rumors, etc. Same when any of us women are leaving his Bible study if his wife is not there. If I stay late to continue a discussion, I stand outside the door so we're not inside alone together.