Me and my oh were talking about this yday as he used to eat loads of junk food before he met me and we are terrible for just nipping out for junk when we cant be bothered to cook, and its not what we want for the lo. That said, i wouldnt mind him having it on an odd occasion as a treat, if he sees it as a treat.
My parents never did, and still dont do junk food so i didnt have it much as a kid, we used to get it as a rare treat when we'd been to the local leisure pool as it was just across the road and we loved it, it really did feel like a treat! Think it was more to do with the play area and ball pool than the food tho to be honest.