So, I'm not sure how to word it, but I hear majority of people say des-ne and des-yo. But following the this: https://japanese.stackexchange.com/questions/1095/what-are-the-rules-regarding-mute-vowels-u-after-s-and-i-after-sh 

It seems that you aren't actually supposed to drop pronunce the u. So my question is, is this some type of special case, or do people just like to make the u silent. If I said desU-ne or desU-yo, would that be ok? Would that sound feminie/mascuine/strange/cute/serious?