Should I tell my man I want a threesome?

So my boyfriend and i have been together for three years. We have our ups and downs but we are madly in love. And when we have sex (we're long distance) it's amazing the best I've ever had. But I've mentioned to him that I wanted to try new things like incorporating another person or couple and he's not really into the idea. He's said he'll think about a threesome but he doesn't seem very interested in the idea and i don't want to force or coerce him into anything. But i can't get the thought out of my mind and I'm not sure of its because I have a strong drive or if something's wrong with me but lately its all I think about. I don't know if i should tell him that this is something i really want to try. Should i tell him or should i try something else all suggestions are welcome and please be kind in the comments.