Congratulations, you are using a word whose meaning you do not understand in order to make yourself look cool, signaling to the people who do know what it means how ignorant and arrogant you are. Just like an Ugly American with a bad Chinese character tattoo, no matter how loudly you proclaim "No, it means this!" - you just look foolish.
"But," you protest, "cis just means I'm not a transsexual!" Nice try, chump. You don't get a word that distinguishes the 99+% of male people who love their penises from [that tiny percentage of male people who experience sex dysmorphia and undergo SRS] in order to clarify your Real Man status.
Trans does not mean transsexual, it means transgender. Thus, "cis" does not mean "cis-sexual." It means "cis-gender." [See thenewbacklash for clarification of terms.]
When you call yourself "cis" you claim an innate identification with masculinity. To anyone who has an actual analysis of masculinity, this means you identify with: war, rape, domestic violence, animal abuse, greed, homophobia. You identify with the unearned privilege bestowed upon you for being born with a penis. You identify with the entitlement to extract labor from women and anyone else you can subdue by any means necessary. When you call yourself "cis" you are flashing a great big neon "I'm an asshole" sign at anyone who knows the first thing about a feminist analysis of gender.
When you call yourself a "cis man," you think you look like this:
When in reality you look like this:
Congratulations on your self-identification.