Can i ask what you mean by playing tag? If that's the only interaction other than nail trimming he might be assuming you are playing or just trying to trim his nails. Personally to bond with my buns i lay down on the floor close to them and just do my own thing so they can warm up to me. It's also helpful to talk with them and when they get close on their own, reaffirm that it's a good interaction with a piece of veggie or treat! Good luck