[He should probably leave this alone, but he's not going to.]

It is not the Empresses who possess conflicting ideals, nor do I believe would they refuse a union based in politics if they believed it to be a proper display of unity.

[He's not much of a romantic, but given that he's the son of a princess...]

These people are traditionalists. If the rebellion continues after the union, there is a larger problem at play, and will need to be dealt with seperately.