Toddler body behavior - fingers in mouth

My husband doesn’t like when my toddler does certain things. I think it’s overbearing when he tells her to stop doing these things because I don’t think it’s a problem. It might just be part of being a toddler. She’s recently turned 2 a couple months ago. The one he really doesn’t like and has been getting on her about is putting her fingers in her mouth. She’s been sticking her index finger in her mouth when she’s watching tv, or in the car or even eating. I think she’s teething or just exploring her mouth but he always tells her to get her fingers out of her mouth. Like to the point of saying he’ll turn off the tv or being done with her food. I think it’s frustrating and not worth the effort. Another thing she’ll do is twist her fingers. This one could be worrisome but could be fine. I don’t know. She will hold her index finger in her other hand and like twist or just like rub it? He thinks she’s gonna hurt her fingers that way and tells her to “stop or you’re gonna hurt yourself” I’m not sure she would have ever until he said that. Like it gave her the idea that it might hurt and get attention. I don’t know there are other things too but it’ll take too long to type.