I kind of like it. By itself, it has a sort of dated, mid-century feel, not something I would picture on a young kid now. But with your other two boys, it shows more of its last-name, British roots origin, and in that context, I like it a lot. Hayes, Graham, and Dean ... it sounds good.
I agree w/Jadzia.
Ooooh, I think it goes great with Hayes and Graham.
I think it would be perfect for you.
Normally this is not a name I would think "ooooh, I like it!"
I like it.
Well a little late but Dean as a first name is nice, but not WOW.