I would like some advice on using butt plugs.I would like to thank you in advance for any advice.I now have a Mistress/Dominatrix who would like to use her strap-on on me. I agree that she may use it on me, but she has suggest that I should get used to the feel on having something up by anus first. The suggestion is I should trying using butt plugs first.I purchase a set of training butt plugs containing 4, 5, 6 inch plugs. I have now been using the small one now for 4 days and beginning to enjoy the feel of the plug.Now here are my questions.1) After about 15 minutes of inserting the butt plug I get a burning sensation near by anus opening. When I remove it a couple minutes later the burning sensation stops. Please could tell is just my splinter muscle getting used to been stretch and will it stop eventually.2) Also as soon as I insert the butt plug my anus pushes the plug out. So I have to hold the plug in place. So does my anus need training to stop this happening.3) How quickly should I move on the next size of butt plug as I would like to try the large one sometime.May I thank you for reading this and any advice you can give me.