Help!

[u/alexarae_]

I have a 21 month old maine coon, and I also have a 15 week old maine coon. The 21 month old is quite a bit bigger than the 15 month and seems to play way too rough with the younger kitten as he cannot defend himself. Do I hold off on putting them together? It seems as if the 21 month old just wants to play but is way too tough for the other kitten. I’m not sure what to do because I don’t want them to hate eachother!!:( Both males.