Demisexual

It is not known when or by whom the demisexual flag was created, but it was presumably created after the creation of the asexual flag in 2010, as it uses the same colors based on the AVEN logo. In both the asexual and demisexual flags, black is black and stands for lack of sexual attraction, and purple stands for the Ace Spec community. The gray stands for Greysexual, under which demisexuality is contained. On the demisexual flag, white stands for sexual attraction.

Demisexual is a sexual orientation on the asexual spectrum, defined as someone who does not experience sexual attraction until they have established a deep emotional connection with someone. The connection can be romantic, platonic, or some other form of connection. What is considered a “close connection” can vary between demisexuals. Forming an emotional bond with someone doesn’t mean you’re automatically attracted to that person, as it just means you now have the opportunity to feel attracted.

It is important to distinguish between typical sexual attraction to friends and romantic partners and demisexuality. In addition, it is important to note that demisexuals do not simply choose to abstain from sexual activity until they know the person better.

Source: https://lgbta.wikia.org/wiki/Demisexual