Expanding our sex life.

Anything like that has to be only if you are both willing and able to accept the consequences of forever changing the relationship you have. Personally I would never do it.

It is not ok to "expect" him to be ok with it unless you had that conversation prior to marriage and he knew what he was getting into. It sound like you want to be "swingers," but if he is not on board then it is not ok. If this is the lifestyle that you prefer and he doesn't then it would be better to get a divorce and find somebody that would be into swinging.

Not that it's unheard of, but I personally wouldn't be into it. Some people prefer monogamy and I am one of them.

If your husband is into it, then he's into it. If he's not then how will you handle it?

I like the idea of 1 partner and 1 partner only mainly for being safe; no worries about diseases and such things.