ok peoples i have a blended famly question for you....

(my family all live in perth too)
my parents divorced when i was 6 and my dad remairried when i was about 10 i think, then this year he remarreid again, so i have 1 mumy, 1 exstepmum and a current step mum... following so far
now i talk to my first stepmum regularly and we were gettign fairly close- i can talk to her and we are friends, she is also the mother of my two sisters, and my current step mum and i can barely put 2 words together - i just took an instant disliking to her and she to me apparantly,
now i was talkign to stepmum #1 yesterday and she mentioned that shes hopingto see me for the christening, and iwasnt sure if i was going to invite her and her fiancee, now i guess my sisters have told her shes invited...

so my question is, i would love to have stepmum #1 here for the christening and im not sure if my dad will fly over with his new wife and i know my mum will be here and im not sure what to do, do i send them all invitations then just hope they all play nice? my dad has suddenly decided that its time he be nice to my mother and try to be her friend - which i know she will not do...

so im at a loss. a christening is supposed to be a wonderful time but with the way that my fathers new wife behaved at my wedding im sure she will probably will throw a spanner inthe works and cause a huge fight!!!

HELP!!