Different partners with different “attributes”

This is less a poly question and more a group sex question. But…for people who have had MMF 3-somes what is the dynamic if one guy is much more well endowed than the other?

Pause here to confirm that penis size is not very important. But I will say that certain positions are easier/better/possible with a larger penis.

I’m thinking about introducing the idea of a 3some to my male partner and, while he and I have an amazing physical connection, he is on the smaller side in that way and I’m wondering if he would be jealous or something if the other guy was more well endowed. Esp if I was able to do stuff with the other guy that he and I can’t do as well.

I know this is such a silly worry but I’m super curious how this has played out for others or if it’s just a non issue.