How come everyone's so quick to point out my "immaturity" when telling a joke but when my boyfriend told?

I think that most people expect boys to tell sexual, immature jokes and not girls. When your in a situation and don't know what kind of jokes to tell, observe what people are talking about and tell a joke along those lines. For example, if a group of people are talking about how the weather is and what they are gonna do over the weekend, its not a good idea to tell a sexual joke. Also if all the jokes you know are sexual and most people know you for them, that may be a reason why they say that.