Just from a different perspective .....
I find this all very contradictory, as on one hand you say that your life is centred around travel ,the good life and your many friends , but then you go on to say you suffer from social anxiety , are hard of hearing a with short attention span , so how have you coped in those situations?
I take it that your SIL is aware that you both enjoy your holidays and socialising with your many friends , so , one would assume from that that you would enjoy the family gatherings also , so no doubt this is one reason why she keeps sending you family invites .
Should we be more open to a wealth tax?


As for not having to explain, it is really rude to not give a reason for declining an invitation but if you don't feel comfortable telling the truth, make something up; just make sure you won't get rumbled! 
