Partner meeting his sister. I'm worried.

[alsteff]

Hi,
We had a phone call early last Sunday morning from my partner's mum to say that her daughter (who had been adopted at a few days old and mum was 16) had made contact & they were meeting next weekend. DP is the second child from the same father (18mths age difference) and his 'new' sister is now 52yrs. DP's mum left their dad for a new partner whilst she was still pregnant with him.
Anyway, I'm really worried - the past 5 days have been very difficult. DP seems to be (understandably) going through a roller coaster ride of emotions & is currently off walking in Wales to try to get some clarity.
His mum has asked him to go with her to meet his sister & although initially unsure, he has agreed. It's a 4hr drive away & they have accommodation & his mum's (newish) husband is accompanying.
Yesterday he said he felt indifferent to it all & to having "found" his sister. I know this can't be true & is some kind of internalisation or attempt at coping.
His mum is a very emotional lady & will also be meeting 4 grandsons & 5 great granddaughters. It just all feels like too much too quickly for me - contact was only made a few weeks ago apparently.
I'm not sure if I'm over stressing about itor if I should be a bit more pushy about driving there with him. I have offered to go but he didn't really say yes or no initially & it's currently assumed I'm not going which is ok but I'm worried he's not as brave or ready for this as he assumes.
Any help or advice welcome.
Thanks

Wow no advice but what a crazy thing to experience for all of you. It's probably too much to process which would account for your DHs indifference. I'd offer to go (as a driver if nothing else) as you have but tbh I'd make this offer to his DM rather than just him. She may appreciate the offer of support and want to accept it or she may need to spend the time just with her & her Son on the drive so she can talk freely. But whether you go or not if they both/all know you're being supportive they'll open up to you about it all once they understand how they're feeling.

No advice followed by advice - I meant no experience sorry, just gut feeling response!

Oh goodness, yes, be bossy. Your MIL has jumped in with both feet, hasn't she? Meeting three generations of a large family at once isn't exactly the recommended way. Insist on being there as support for him. You might be able to inflict a bit of pace on proceedings, or at least take him off for breathers.

If he's lived with her ways all his life and he's not desperately communicative (the vibe I'm getting), he really does need some sensible back up.

Thanks. It certainly feels like jumping in with both feet but I get the sense this is coming from his sister's side & perhaps she feels more secure with her family around. There's an initial meet I think, for mum & daughter, then 'all in' the next day. FIL is a sensible man & will be trying his best to pace things but even so I'm not sure how much influence he'll really have.
Obviously the opportunities here are potentially so positive but it's definitely going to be emotional overload! It's really come at a time when we personally, have a host of other issues (counselling with preteen, huge work related stress etc..). Oh jeez I'm rambling now!

I'm sure i've read you're supposed to have counselling and talk things through before you rush off to meet long lost siblings.
There's that thing about sexual attraction he needs to be prepared for at the very least. I'm rubbish - i can't remember which charity it is he should contact but someone here will know.
Anxious that i don't sound like it's a bad thing to meet siblings - just a bit less rushed.

FIL is a sensible man & will be trying his best to pace things but even so I'm not sure how much influence he'll really have.

Two of you as "ballast" for two of them makes sense then. Just cheerfully insist.

How did it go?

After Adoption is a charity that may help.

Hi, it's this Sunday he's meeting his sister. At the moment I'm trying to heavily influence MIL to tell her daughter about DPs existence ie "you have a full brother" before the big meet but she's quite convinced she wants to tell her face-to-face which I understand in a sense but think is a poor decision. I wonder if the reluctance has a tinge of guilt attached. Currently having visions of DP jumping out of a cake shouting "surprise"!!!! Surely the more factual information beforehand the better as it will give more space to emotions in meeting.