I think your sister loved him and would want him to be happy. That's what I'm going with. And if she can't be there to do that, it has been a year and a half. If she's a nice lady and he's happy, I'm sure sis is smiling down on them.

Of course, I say that as the woman who has sternly warned my husband that if I go first, he best not find anything or anyone more than my memory to keep him warm. I can and will haunt a bitch, for real! LOL