3 somes ..

so, i have been with myboyfriend for about 4years now.. we have just recently had a son. Our relationship is great ..but were alittle bit jealous when it comes to other females like i cant give a female too much attention without my boyfriend being concerned.. but we would LOVE to be able to have a 3 way with another female.. the thing is im alittle scared he may become more inatamant about other females since im the only one hes ever been with.. also i wouldnt want them to end up having an emotional connection somehow, & id like.her to not be to sexy ..if im jealous of her body ,i am 100% that i will not be willing or happy to let my boyfriend see her naked lol ..but why is having a threesome with him seem tk attractive to me why do.i want to have one so bad if im being so picky.. id like advice because this is something i want to do but also i want it to be a great expierance for him & i without any jealousy..good idea ..or bad idea? Any expoerances out there?