To Not Want Strangers to Join a Small Family Event?

[MischaPop]

One of our Christmas family traditions is to go to a Christmas event at a local attraction. Usually as well as myself there is DP, DS, DM, DF, DMIL and DSis attend (Also sometimes DSis partner) We are looking to book for Christmas 2018 and DM has invited a couple that nobody else has met. I have told her I would rather keep it to family only. DP and DSis agree. I just think two strangers coming along changes the dynamic quite a bit! Would like opinions on whether IBU. DM is not happy that I would prefer her friends didn't join.
(Post edited by MNHQ)

The cynics on here are irritating. I have had similar accusations twice when asking about specific companies/ events. Lots of sage head nodding and marketing murmurs. Made the accusers look like conspiracy twats but meant the sheep followed on and both threads took turns for the worse. Just report ir if you think it's a marketing con.