You hired Vin as your bodyguard for your safety, but you didn't know he had a crush on you. He doesn't confess because he's scared to lose you so he just stayed silent.

One time you we're talking to your friends and Vin is just sitting on the couch, then your one friend decides to do something fun~ so she pushes you to Vin's lap and they giggle

Your friends leave the two of you alone so what are you gonna do~?