If your relationship revolves around 'as long as our connection is the strongest' and 'will be love someone more than me' then you will spend the remainder of it doing nothing but worrying about what he's doing (and with whom) or looking over your shoulder for the prettier girl.
Either he loves you or he doesn't and likewise your connection is either solid or not. You simply cannot spend your time worrying about these things...talk to him and tell him your concerns. Set boundaries and each of you follow them- if you cannot clear this hurdle then a poly relationship will drive you nuts! Have some faith in your partner and your relationship with him. I will bring you peace
Me- Linkin Park- the husband. I am the youngest, fast paced and admittedly full of issues.
Nina Simone- our wife- slow, gritty, and sexy like a smoky piano bar and a glass of brandy.
Led Zepplin- our wife - a rocker little tomboy that loves with everything. All she's got or nothing at all.