Help me co-sis is one of the issue here

-just ignore him.when you go to IL's place do not try to be around him and just go away from him.make him come to you.

 

I would say give back the reply politely; as you are pregnant now don't leave any chance . If H says something to do (showing bossism/dominanace) ...don't do immediately take your own time and do it later. If he urges you again and again say politely I got other important things to do ...if he feels that has to be done ask him to do it.

 

apple123, I'd say, ignore them. You meet once in 2 months maybe? Completely ignore him when he behaves funny in front of your co-sister. And yes, like someone mentioned here, when he yells at you, keep your calm. If possible ask him then and there the reason for his misplaced anger. If he has a real reason he might venture a reply.
How does he behave when they are not around? If he is normal with you, just forget all this and continue enjoying your pregnancy. And yes, talk to him when possible, about being more attentive to you, without bringing out the topic of his behaviour in front of her.
All your tension won't be worth it at this stage and it might only create more trouble if you decide to react on it. Vent it out here if necessary or talk to someone at home or even your in-laws. I understand that can be very difficult to watch even if it were once a month. But just learn to look away.