the jealousy thing is normal if you are first starting out in the LS. you need to look at it as you are his. he may have other subs but that's part of the LS. if you are not at the point where you a good sharing perhaps ask your Dom to not talk about the others and just focus on you when he is...
talk talk talk! set boundaries don't do anything you don't want to do ever! it all has to have fun and live life to the fullest. trust is a big thing but that takes a lot of talk and being comfortable in your skin.