Had something similar happen a few years ago. I feel for you. Lucky a simple solution exists. just throw a light jacket on and say your cold.

Haha! This is awesome.

I don't get why everyone keeps saying OP should have explained. The grandma doesn't speak english. I'm guessing OP doesn't speak grandma's language either. If she did she would have explained why the shirt was innapproprate and would not have been forced to wear it in the first place.

You couldn't have worn a jacket??

Consider this: the grandma doesn't speak English and it's very possible OP does not know the language. Additionally, there are many cultures where bondage isn't even common knowledge so had s/hetold her what it meant, s/he would then have to go into detail about what bondage is. Now, we don't know how old OP is, and in many cultures, the grandma would scold him/her for even knowing (I know I would get scolded). And when a relative gets something for you, ecspecially an elderly relative, and wants you to wear it and you don't, it really does hurt their feelings. Plus, look at OP's location. Egypt. Now I'm not generalizing, but I know many Egyptians who, like me, are Muslim. Even Egyptians of other religions are rather conservative. The point being is it that it was a better decision to simply wear the shirt with zero ***** given rather than going through the whole process of explaining what tying someone up while pleasuring yourself or them in a rather rough manner is and how she accidentally got OP with the name of that action on it.

plot twist: grandma knew exactly what it meant

Wear a jacket?

If you're a girl hide it with your long hair