Urban Dictionary defines a Fuckboi as such: A guy who will tell a girl anything to get them to hook up with them.

This is not the way of the modern Dude. We are better than this. This is a shitty thing to do to women, which leads to mistrust in the next guy she encounters. Don't screw the next guy! Not to mention the inflated sense of self that it makes you feel. It is very unhealthy to go down that road for your mental.