He lied... again...

So my husband was in the group chat with his friends and some of his friends have sent extreme porn on the group chat and really nasty comments about women in general. I told my husband I am not really happy with him in this group? Even though he doesn’t comment or reply, i just don’t want him part of that circle. So he left the group. Four weeks later, I later see that he is re added back in that group again and when I asked him he said that they added him yesterday and they kicked the dirty friends out of the group so there shouldn’t be a problem however when I checked he was added a week ago (lied to me) and I’m just upset that he hid it from me because if he knew that we argued about this group chat in the first place he could’ve told me oh they’ve added me back and the dirty ones are not in the group? What do you think? But he didn’t even mention it at all and I KNOW HE WOULDNT HAVE IF I DIDNT SEE THE GROUP CHAT TODAY!

What shall I do.?

Let him be and if there is another dirty or disrespectful encounter to voice me opinion then?

He lied and he should know better than your not happy with it, be upset with him?