Honestly? Enthusiastic consent. I can overlook physical features that might not be my favorite if she's enthusiastic and direct about what she wants in bed.

My wife is on the spectrum, so unfortunately while I know she is enthusiastically consenting in her own way, from an outside perspective it would seem like she's not at all into it.

Her version of enthusiastic consent is, "if I didn't want to do it, I wouldn't." Which is fair, although it does cause me some anxiety. And yes, we've talked about it and she's working on being more obvious about it.