If you're being contacted by CaL members, outside of the forum, like on FB Messenger, among other platforms, and you do not want the person to do so, please let the person know this, clearly. A close-ended response such as, "Please do not message me.", is polite and very clear in its meaning.
If the person persists, then please write to moderators@chefatlarge.in with screenshots of where you've asked the person not to contact/message you and they have persisted in doing so. Having said that, we can only remove the person from the forum, which does nothing in preventing further messages/communication from them, which you'll have to take preventive steps such as blocking etc.
Personal interaction, attraction even, is a natural phenomena. If someone does message you expressing emotions or sentiments that you do not reciprocate, please simply ask the person not to message you. If they persist, only then it becomes harassment. If you do not respond, the person who sent the message has no way of knowing your thoughts on their actions.