Stressed out sub(f)and giggly new dom (m)

I don't know where to put this and I don't have any friends I can talk to about it.

So I've known about BDSM and my kinks for 5 years now. I only really started have sex regularly for the last two years.

My boyfriend (20) and I (19) have been together for two years and we are long distance. I have brought up the idea of being submissive to him outside of sex before and he always giggles and says "sure." To me that doesn't feel like he's really interested. He's new at even being dominant during sex. I understand this is an easier mindset for a lot of people to get into.

We have planned to live together for most of the summer. I feel like that would be a good time to start because we would not only be having more sex but we would also be together more. We are able to communicate about important things, hell we've even talked about kids (8-10 years if we are still together) but when I try to talk about BDSM he giggles.

Any advice?