Why would my boyfriend react weird to a joke?

[ChinaRose1]

hi recently me & my bf moved into a house together, yesterday there was a little sock in the laundry basket & he said was it mine (but i no it was his little nieces because i saw her with them on) and i said 'no, one of the girls youve had round must of left it' as a joke but it came out more grumpy & serious than i expected , but his reaction bothered me i thought he would be like 'oh yeah one of the millions' but instead he said 'what?! what are you talking about you weirdo!? no girls been here, noone nos were i live' hes normally jokey but this bothered me for some reason but i dont no if hes trying to hide something or he couldnt tell i was joking!? help plsss its bothering me!! thanksss

 

[Mich]

I think you are right to be a little suspicious, maybe try askin him some more say he been seen with another girl or somethin(you'll have to figure how to try trap him, cuz u will know when he would have any chance) then see how he reacts to that! If he's chilled and jokey about it then he might have just been in a bad mood with the sock! But if he's all defensive again it's somethin you need to talk about!