I have a group of friends who I sit with on the bus. Usually, they have fun talking while I watch and listen, which I'm perfectly fine with. From time to time I join in to their conversation, which usually involves a fair amount of teasing ("banter"), which inevitably involves me at some point. One of the biggest reasons that I stay quiet is because I'm usually quite tired on the bus and can't come up with clever comebacks easily.
I have absolutely no problem with their banter being directed at me, but I tend not to react much since I'm not that good at coming up with comebacks on the spot. For example, at one point this conversation took place:
Friend 1: (joke about me addressed to me)
Me: (doesn't really react, has a blank face for a moment since I wasn't expecting to be addressed)
Friend 1: Oh no, I didn't mean to offend you! I'm so sorry!
Me: No, it's ok, I'm not offended at all :)
My friend however didn't seem to believe me and seemed to think that I was just brushing it off while being offended, so continued apologising. This resulted in another friend making a sarcastic and somewhat annoyed comment:
Friend 2: It's all fun and games till she (me) gets hurt.
(In the UK, and also elsewhere I believe, people who "can't take the banter" are seen as annoying and wimpy/destroying the group's dynamic.)
I want to avoid a similar situation again. How can I point out that I'm not offended in a convincing way? Preferably in a way that isn't overly serious so that I don't perpetuate the "delicate wimp who can't take a joke" perception.
Quick note: I am good friends with these people, and their perception of me as someone who can't take a joke is not one which they dislike me for or tease me about (if anything, they tease me less because they see me that way).