Good Ray Tank Mate?

So my teacup ray is currently alone and my payara is outgrowing his tank I've had him in (20g long, he was about an inch when I got him). He's around 3 maybe 4 inches long now and I have nothing in my 75g tank except the ray. Would the two of them be okay together? The rays disc is probably 5.5 inches across and like I said the payara is max. 4 inches long. I'm having a really hard time finding any post or article on any website that has info about these fish together. Any help will do! I'd love to have the two fish together!

And also, I do not plan on keeping either fish in the 75g. I just picked up a 300g last week and I'm moving in the next 6 months to a year out of state so I'm not gonna set it up. I also have two 135g tanks with room once these guys get bigger if they don't make it a year in the 75g. Just clarifying that!

Awesome thanks guys. Have Monday off, gonna go ahead and put them together!

Here's my little ray by the way! First crack at a stingray, got him (I believe it's a boy) a little over a week ago. Seems to be doing good! Eats bloodworms, seems healthy! Only concern I have is I haven't seen many adult teacups anywhere.. On the forum, google searching, etc. I've always heard these guys can be temperamental, but how common is it to get one to live to adulthood?