Recently, with the WC game, some English friends talked about "kicking Yankee asses"/"teaches those Yanks about real football". I found that a little offensive.
I just laughed and said "You limeys are going down!" and they thought it was hilarious.
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There were also a lot of jokes about DH sleeping with the enemy, etc., so it was a fun night with lots of laughs for us. DH kept saying I was the most popular person in the room because everyone was joking with me when usually they kind of ignore me or whatever, so at least there's that!
But there was one point where one of DH's friends starting singing "If you hate the F***ing Yanks, clap your hands" while another friend clapped in my face. I pushed his hands away from my face and gave him a dirty look and they could tell they had gone too far because even the rest of DH's friends were silent and staring those two like they were being jerks, so they immediately apologized and said they were just winding me up. But you know, I didn't mind the ribbing at all until that moment. Thankfully it isn't the sort of thing I have to deal with all the time, and they were wasted, so it really wasn't that big of a deal, though I was pretty mad for a minute or two there. At least they apologized and seemed to mean it, so all is forgiven and I just laughed it off in the end and enjoyed the rest of the night. Those two guys are usually really nice to me and have bought me drinks in the past, so I know they don't actually dislike me or anything so I didn't really take it to be as malicious as it sounded.