I haven't bothered to name change, as I don't care if this is recognized. My BIL is in his mid twenties, and has graduated with a degree. He's been screened for everything, and while he has ADD (like my DH), there are no other issues present.
Tonight we had my MIL and BIL (who lives with her) over for pizza to spend time with our DS, who is two years old. The invitation was issued to them both. While DH was out picking up the pizza (they arrived as he was leaving, as they showed up a bit early), BIL repeatedly teased my son over the course of the night, even worse than the last few times we were all together. (To avoid a drip feed, yes, this has happened before, and each time he's been asked not to do this.)
Tonight DS was running around asking for a cookie, and BIL offered my toddler a closed fist and told him he had a cookie in it for him (he didn't), and promised to give him the non-existent cookie if he did what BIL wanted. I obviously intervened immediately and told DS BIL didn't have a cookie and asked him not to tease DS as it would hurt his feelings and make him cry. BIL laughed it off and claimed DS didn't understand. I assured him he did. MIL didn't say much, but appeared to back me up. This happened again with something else (a toy), and again I intervened.
DH came home with the pizza, and BIL quickly grabbed a slice while we were getting DS's piece cut up as it was too hot for DS to eat. BIL proceeded to tease DS, dangling his pizza in front of him and asking if he wanted it, saying he couldn't have any. Then he started eating it in front of him and making "mmm" sounds, and taunting DS.
DH intervened immediately, telling him in no uncertain terms not to tease our son like a dog. BIL laughed it off yet again, saying DS "didn't understand" (he certainly did). MIL chimed in backing DH up. BIL laughed her off, too. Finally, I stepped in, stopped the conversation, and told BIL flatly not to tease our son. While that was all I said, I can be quite intimidating and BIL was embarrassed at not being able to pass it off as a joke.
That seemed the end of it, but throughout the night he continued pretending he was going to take my DS's candy out of his hand, etc. AIBU to not have him over anymore? Taunting DS with our food (that we paid for) in our house seems to be taking it a bit far. Especially since the only acknowledgement he gave was an "ok" and not an actual apology. At this point, I can't see having him over for holidays either, as I don't want DS's holidays spoiled. DH agrees, saying that if he wants to see his brother he can do it on his own (which obviously is fine).
We're reasonably certain that we can still see MIL on her own without BIL, but would rather there not be a problem as they live together. Thoughts appreciated.