Need help with nipping bunnies

We have 2 six month old neutered bucks. They have their own room and we go in to spend time with them in the evenings. They know I will always bring them fresh veggies in the evening. They have starting nipping at my husbands clothes and getting his skin with it. Not sure if they are asking for more or grooming him, but I was hoping someone had some ideas to get them to stop. It makes him not want to spend time in there . I've tried thumping but it only stops them for a moment. Advice?

My doe did this on me, I would only give her reward/ food when she didn’t nip.

If she nipped I walked away, so she learned at last to lay her head on my knee if she wanted to be groomed. While asking for food, she will put her front paws on me and run around, instead of nipping.

She learned quite fast she didn’t get what she wanted with nipping, so she stopped with that behavior.

What type of clothing is he wearing when they do this? I have a rabbit that has a problem with raised letters on shirts and would do this, I had another who if you would wear flannel PJ bottoms would do this.

Why I don't wear long pants--our first bun loved to chew holes in my Levi's , sox and really liked shoe laces. She never bothered the computer or phone cords. With biters I'd grunt at them or tell the "NO!" in a harsh voice and roll them on their back and pin them like an alpha rabbit would do. A friend of ours held his bunny facing out so she couldn't nip his arms. She spent a week with us and she no longer bit to get put back down. Told him if you don't train your bunny they WILL train you. Seems like all like to dig at and nibble clothing. Got velcro tennis shoes as it was easier than keeping shoe laces on stock.

http://language.rabbitspeak.com/

When returning from the humane society, our spayed rex girl wanted to nip/bite my ankles and socks. She didn't like the other scent of rabbits on my long pants. Her neutered bonded husbun wasn't a concern, but she was very attuned to other smells of strange pets! She wanted to protect her space and smells of other animals on my shoes/socks/jeans was troubling. -- She mellowed as she aged, and knew that no one would harm her.

myhouserabbit.com - https://myhouserabbit.com/rabbit-behavior/help-rabbit-hates/

http://www.mncompanionrabbit.org/rabbitcare -- helpful articles on the R-hand side tabs

http://www.rabbithaven.org/biting/

If we have a nipper in our network, I do the loud "eek" and "thump". When our rex girl bit me so **** hard, and blood poured out, I slipped into actress mode and began sobbing. You should've seen the look on her face as I cried for more than a minute. Redirecting the nips to a positive behavior takes time. Our formerly abandoned sable girl would constantly dig and nip at me, whereas she was fine with hubby. She preferred hubby over me. Something in her background perhaps ?? re: female scent.