My BIL keeps making annoying comments

I’m 38 weeks pregnant and my SIL invited us over for dinner tonight. Their house is 35 mins from ours. When BIL found out he was like “knowing my luck, I’ll have to deliver this baby.” Last time we went over a few weeks ago, he said to her “I’m not delivering this baby if she goes into labor here.” Like nobody is asking you to, my husband is there, and you’re just being weird and rude??? Idk I think it’s so weird. He’s an ex-EMT, which is maybe where this is stemming from but I mean like how much training did you receive in delivering babies? Why would you think of this/say something about it/say something about it multiple times? I think I’d just drive to the hospital as planned ideally.

Edit: this is all behind my back and my SIL tells me about it after the fact. None of it has been said to me. Idk I still think it’s weird