Personal jokes that seem perfectly hilarious in the indulgent hush of one's own bedroom sometimes (often) fall flat (splat) the moment an actual audience (mom) is introduced.

当你在自己的平淡无奇的房间里肆无忌惮的释放自己时，恰好你妈妈进来了，你自己出洋相似乎就是个笑话。