My boyfriend is much younger then me.
My family and friends are nice to him but when I'm alone with my friends and talk about him they sort of shrug it off and they don't ask me how he is or how we are doing.
We live together and get along great.
We both know that the relationship will not last, he wants children and I've already done that but we are happy in our moment.
I feel like no one takes us seriously because of the age difference. We have been together for 10 months.

No one takes it seroiusly because you don't. You said, "it will not last" so you make it sound like nothing, I assume that they do not wish to waste time on it either

I agree with Fr_Chuck... the first thing that popped out to me was you saying that you know it won't last... why should they invest any time into it if it's not going to last?

You also don't say the ages involved... that could be an issue also. Not just the age gap, but the actual age.