It doesn't sound offensive don't worry! I actually made a comment talking about this yesterday, which you can find here. I'd recommend reading that, and then coming back to my response.

Being a lesbian is actually not nmlnm, that is one of the common misconceptions about this identity. /nm /info Nmlnm is more applicable to wlw or sapphic than it is to the term lesbian. Being a Lesbian is to be queerly attracted to women in some way! This can include cis men and trans men being queerly attracted to women, as long as both are using the term in a genuine, non mocking way