I think since living with DH we have both rubbed off some (good) habits on each other and we have changed some of the things we used to do before SO came around. For example, he used to re-use Ziploc bags (as in washing them), I told him I thought that was excessive and he has since stopped. That may not necessarily be a good habit, since it's not very earth friendly but I have changed that habit for him nonetheless.

Since being with your SO have you changed the way they do certain things? Have they changed the way you do things?