If u think some1 not treating u nice, u have to say it out, if they are childish thinking, unmature, they think that u are kiam siap, then that is their business.

The best thing thing is to tell ur behalf about ur feeling, dont drag until thing getting worse then only bring it out.

Anyway, since u are together with him u have to get a long with his family no matter what. Whatever it is, just be nice, patient and avoid arguing with any1.