My rule of thumb is that I only make "edgy" jokes in private, amongst people who I can be certain of the reasons why they are laughing. One might think that everyone is laughing for the same reasons you find the joke funny, but often they are not. (Chris Rock and Louis CK have both removed material from their routines for this exact reason)

Another issue with offensive speech is that it normalises behaviour and thoughts that may be far more pernicious than a tendency to make jokes. If you have one of "those friends" that tells a disproportionate amount of (sexist/racist/rape-based/etc) jokes, it may be the case that you laughing along is actually justifying/enforcing beliefs they hold that you would find reprehensible (and likewise for you telling jokes of the same nature in their company)

As we are all subconscious sexists (there's a link up-thread to a study on blind hiring as an example) there is also a very real danger that you cause harm to your own mind (in the sense of creating or reinforcing bad behaviour and opinions) by engaging in humour or speech based on sexism, even if you don't think you believe the underlying sexism that you are lampshading with the humour.