I try to avoid telling people unless I know I can trust them, because sometimes women won't look at me the same way, and men will be all gross and start rambling about how they wish I would be in a threesome with them or kiss girls while they watch. Because apparently they think that my orientation is just a performance for them or that I must want multiple partners at the same time because I "go both ways"
It depends on your environment. If you know the people well enough to gauge their reactions you can go from there. If you don't know them well enough to predict their response, it can be dicey.