You are OK, Okeydokedeva. I know you didn't mean anything sexual by the word, 'crush' I looked up the dictionary definition and there are many but this is the one I think people were concerned about: "INFORMAL a brief but intense infatuation for someone, especially someone unattainable, eg:
"she did have a crush on Dr Russell" "
Don't worry about it, you won't use the word in that way again and you didn't mean it that way - we all realise that.
The children are friends. Small children do go on and on about their special friends and always want to see them.
However, the other child's mother finds it all a bit much at the moment. Gone are the days when we could drop our child off at a friend's house for an afternoon, then go home and put our feet up, or visa versa. Now parents have to visit with other parents while their kids play. I'm sure that can be a pain; not everyone likes sitting in someone else's house, they'd rather be at home doing their own thing or even having a nap. The mother will feel even more that way when she has a new baby.
Just leave it, Okeydoke. Your little one will make other friends, you'll see, so will the other child and so will you. This situation will not last forever, or even for long. Please try not to take it so personally or seriously. Child-politics can be difficult to navigate, try to be cool and casual about it. I've no doubt you have fun with your son so concentrate on that.
I wish you all the very best. Take care of yourself.