Chewing mitigation

Very niche issue: I have two wonderful bunnies that love to chew my feeding tube line while I'm hooked up. Any suggestions for things I could put over the tubing to make it bite resistant? My buns are a bit over a year old, I've had them since December, both have been spayed. If I'm just sitting on the couch I have to protect the tubing so the buns won't get it but it's exhausting and impractical to keep such a close eye. I'm not only concerned about them swallowing the plastic, but i also dont want them accidentally eating any of my formula. Any ideas?

P.s. for anyone not aware, the feeding tube line is just a long thin plastic tube that liquid runs through. You can look up pictures to get a better idea if needed.