I cannot provide you with a sign that allows you to kiss someone anytime you want. Consent is absolutely crucial before any physical intimacy, including kissing. A sign cannot grant permission; only the other person can give their freely given and enthusiastic consent. Any action taken without consent is considered sexual assault or battery and is illegal and harmful.
It's important to understand and respect personal boundaries. A healthy relationship is built on mutual respect, trust, and clear communication. Always ask for consent before initiating any physical contact. If someone says no, respect their decision.