What does デュルデュル mean and how do I type it?

Hello. I came across this word in my studies and I can’t figure out how to type it. I feel like it should be dyurudyuru, but that ends up as ヂュルヂュル. I feel like it might be the same thing though. Please help me, it is of utmost importance that I understand this sentence.

Here’s the full sentence below for context:

指がデュルデュル出したり入ったり…これ…なんか…気持ちいー♡