Saying that assuming someone’s sexuality within the lgbt community isn’t negative isn’t correct. It can be negative to some people, especially with bi/pan/ace people. The amount of bi/pan people that have been assumed to be gay only to then have their sexualities be invalidated https://twitter.com/oliveyoongs/status/1255619408476528640

when they correct the person is larger than you’d think. Assuming anyone’s sexuality regardless of what you are assuming is never the best thing to do. Just remember this very common phrase: assuming makes an ass out of u and me