I have a 5 year old male that's about 60kg,quite a big dog,I can't for the life of me to get his knot out of its sheath,he's always interested and tries to mount me but can't really get his knot out and I don't want to hurt him or smth, I read somewhere that if he gets swollen in the sheath it's quite painful for him, I have seen him knotting my female dog some time ago,how would you advise me to go forward with this? I'm quite new to all of this