What is Handcuffin?
1.
taking extra care to make it known that the person you are with is your significant other, includes: public displays of affection, holdin hands, cuddling, speaking for the other person
Stop handcuffin nigga, we know that's your bitch
2.
when you decide to date someone exclusively, but usually after only knowing the person for a short amount of time
Dang, man! You handcuffin' with Stacy already!