ADHD Husband doesn't like my ADHD Sister

Hello, 

I just wanted to look for support or help since I don't know how to handle the situation. My ADHD husband is not on medication, he's going to the gym to help him manage it. Doesn't seem to be working tbh... but anyway. My sister and mom are here for vacation, its been about a month now. They will be here for two more weeks. And whatever my sister does aggravates my husband. My sister is diagnosed, not managing ADHD, and no meds. 

He gets annoyed whenever she talks. He says that my sister has a crush on him. He is rude at times to her. He doesn't like being around her says that whatever she does triggers him because he feels like crap cause he's done the same to me prior. But before he was diagnosed he didn't have any of these issues and actually pitied her. Now, its this insanity or what feels like insanity. I'm caught in the middle. I don't know what to do. I don't think I've even given a good explanation about the situation. I just... I'm at a wit's end. I guess, I just wanted to know if anyone has observed their ADHD spouse interacting with another person with ADHD and how that usually goes...