How to not become sandwich

so I am working in a company where I hangout with one of my colleagues (random name sonu) most and with other teammates also I have good relation but I don't hangout always with them they go in a grp for tea and all I perfer one and one conversation not a grp person but still I go once or twice in a week but sonu mostly. now sonu and few of the grp member have ego clash but also they random shit happily like about bike ,trip and many more but when it comes to work then ....... u know ,now our boss take us for dinner and drink there if u see them u will say they are buddies in front of boss they pretend taking care of each other and booking for each other as everyone is drunk but I know they don't give a fuck.

now issue is that grp person wants me leave him alone and join them and whenever I talk with them one on one they complain me of him that he is like this, he do this and bla bla..... many a times try to give justification and say to sonu what they were taking about him and he use to say his issue which I never say back to them. I am not saying that sonu is innocent, obviously not in front of boss he is like "hum saath saath hai" and after that "hum aapke hai kon" . I am tried of all these things . I want advice how not to give fuck of these things and focus on my growth and keep my mind calm I told many a time to each of them I am not going to be ur messanger u talk ur issue ur self like u talk other things nicely but they say u don't understand there game (each others game) I know they are paying there but I don't know and don't wanna participate in this games ,I think I will be 1st to get cut off .