How to nibble
Start off by incorporating slow and soft bites into a hookup, bite their bottom lips lightly to get them comfortable with the idea of using their teeth as a sex toy. When in missionary position kiss and nibble up your partner's neck - the neck has a lot of sensitive nerve endings and using teeth here can feel dangerous and animalistic. Never bite too hard as it would leave a visible mark and you need to seek permission first, especially if they're seeing their parents or have a big work meeting coming up!
Always be gentle so the experience is playful and positive. Ask him if you can bite a little harder next time. Getting consent is important, especially when it comes to biting because a playful nip, vs a bite that leaves a mark, are two entirely different things. Make sure you stay away from sensitive regions like the nipples or sexual organs - if you do want to try it out though start with grazing your teeth around the area without any pressure. Then try closing your mouth still not applying pressure, if they want a little pressure to be sure you’re not actually biting - rather just teasing. If you’re the one wanting to be nibbled ask for it be direct and tell them you love the feeling of tender bites and where you like them or show them what you enjoy by doing it to them.