Not gonna laugh. Just gonna take a shot at making up fictional hypothetical strange answers a person might give to these sort of questions, just as an exercise.
- "Excuse me. What's your name?"
- I forgive you. (This is a response to "excuse me", taking a different meaning from it. This is a joke, but may fly over some heads and lead to having to answer a follow-up question such as "what?", which could be responded to with something along the lines of "You apologized for asking, so I forgave you. My name is so-and-so. And yours?".)
- "Do you have a girlfriend?"
- No, do you? (This is a joking subversion of the heteronormative nature of the question, while at the same time shifting the focus to the other person, which shows interest in communication and also gives the other person a cue to inform you about their preference and relationship status, whether such information is of interest to you or not - you're just making conversation.)
- "Can I ask you an indecent question?"
- There is no such thing. Questions are how we learn, how we grow. It's the most valuable thing we have as a species, don't you think? (This is a statement against shame and for curiosity. A positive message. It's true, it's simple, and it's important. Worth mentioning to anyone who seems to think there's any kind of shame in asking questions.)
- "Do you only date women?"
- In theory, yes. (I honestly have no idea what this response would be taken as if said with a confident smirk of self-parody, but I find it kind of amusing in theory.)
This is all hypothetical, of course. I've never had this conversation, nor have I ever wanted to. I'm coming at this from the perspective of a writer.