That is totally different.
If I were in your particular situation I'd check with my husband to make sure he is at least mostly on board with making things "official" as the guy seems like he is a bit uncomfortable thinking your husband isn't thrilled so you actually KNOW what he thinks.
Then I'd say "I talked with my husband about things and he is fine with us getting involved (what is it - sexually? romantically? that you are waiting to take the next step on?) and I really like you and wonder if you have interest in being my boyfriend/would like to spend some time alone with you at your place so we can be intimate/have private time together/get naked and roll around" or whatever it is you want the next step to be.
One thing that's important is to not assume "he is uncomfortable overstepping" but to be able to discuss those things openly, ask him if he has reservations and what they are so you can address them, tell him about any boundaries you do have, be clear that doing ______ is not overstepping anything and you'd like to see if he is interesting in doing _____________.
Happiness will never come to those who fail to appreciate what they already have.