AIBU about MIL new partner

Absolutely love MIL to bits and she is so excited to be a grandma (we have a 2 month old), but she has recently started a new relationship and my OH and I do not like or trust him. We also don't want him to have anything to do with our daughter. He is a recovering alcoholic (spent last month in rehab) and I've got a strong suspicion he is using MIL for money etc, as she is quite well off and he is not. He also smokes a lot. We have gone from seeing MIL on a weekly basis to barely every month, but she only lives a few minutes down the road. I messaged her today to see if she was around and she said yes, she would love to see us but her partner is round too. Am I in the wrong for not wanting an ex-alcoholic, who we don't know or trust, around my baby? MIL keeps going on about how she'd love to look after her, but I don't want that if he is in the picture. My dad was an alcoholic and there's no way I would've trusted him with my daughter. MIL is getting the impression that no one likes him but she seems happy, but it's now affecting her relationship with us and her new granddaughter. Am I being unreasonable? We haven't said anything to her, but I think our lack of visits speaks volumes. It works both ways too, and she has barely been in touch with her son since the new partner came into the picture.