Some people with a kinky side keep that side hidden from family and friends out of fear that they´ll be treated differently or even lose contact with them. I won´t say that this doesn´t happen because it does happen and it sucks, but then again if your friends treat you differently because of something you like then they´re not really your friends. Family is a bit more complicated, you can´t pick your family so you might be even more reluctant to tell them about your kinky side but sometimes family can suprise you and be supportive. Unfortunately not everyone has that much luck.
Do you have to tell your family and friends about your kinky side? No you don´t have to, maybe there are Doms/Dommes that forces their sub to tell their family and friends but I disagree that a sub has to do that. Because with this being so personal I find is unacceptable for a Dom/Domme to mess with that and any decent Dom/Domme wouldn´t do that! Maybe it´s a friendly push to help a sub, but it´s best not to mess with someones personal life. There is nothing wrong with support but there are limits and ruining someones life seems off limits to me!
How do you tell your family and friends about your kinky side? If you´re uncertain about it then I´d suggest you think about it some more before you tell your family and friends, because once you tell them you can´t take it back. Of course there is nothing to be ashamed off, but sometimes it´s better to keep your kinky side and your family and friends side separate. They don´t always mix that well and it´s sometimes difficult to explain to family and friends why you like certain kinky things. It´s sometimes easier to just keep it from them, but I can understand it can be difficult to not include family and friends to a certain part of your life. Just be careful with what you say and remember that not everyone will understand or accept a kinky side.
I think crossdressers have a difficult choice to make when it comes to telling family and friends about their crossdressing side, which sometimes becomes much more than just dressing up. I´ve heard several times that people are scared to tell their family and friends because they think that they won´t be accepted if they would know. It´s tough to tell them and sometimes it´s better not to tell them, especially if you´re pretty certain that they won´t accept that kinky side of you. I think you know what´s best and if you should or shouldn´t tell family and friends about your kinky side. Just remember that there are friendly people out there, people that accept you for who you are and love that kinky side just as much as you!