Stand up for yourself
In case your pretending friend is hurting you, you need to act immediately and stand up for yourself. You need to have respect for yourself and be respected. It is not required that you should be mean or snotty. Simply say ‘hey, was that nice’ etc. If there are more people around then it is highly likely that at least one of them will come for your assistance. You should not let him/her make you suffer and act as soon as possible. Forget about the consequences and do not allow him/her to treat you like this anymore.
Talk to your friend in private
There is a chance then we do not know what will happen when we get in flow. In case it happens, you might not talk to him/her for a day or two. However, after both sides are cooled, you can talk to him/her privately. You should let your friend know that he/she has hurt your feelings a lot. Do ask him/her why he/she uses you as the center of all jokes or pranks. It is possible that he/she will avoid this after he/she reflected your questions.
Make yourself heard
If your friend promises for not hurting you but continues to do so, you have a bigger problem. If he/she does not care about your feelings, you should not care about him/her as well. You should stand up again and stand the problem. Do not hurt him/her or be mean. Remaining people present over there will most probably back you up.
End the friendship
If the person does not respect you no matter how much you have tries, it is time to end the friendship. He/She is not worthy of being your friend. You will now have a chance of finding a friend of better caliber now.