I've not seen my DM (74) since Feb '20 - we live different ends of the UK (5hr drive) and due to both her and her DP having medical conditions, and him needing a big operation at the end of last year, they've been doing maximum shielding. They both have their own houses but she's basically moved in with him, which I guess is nice as otherwise it would have been pretty miserable and lonely...
They've now both had their first injections and my DM has suggested meeting up when lockdown lifts in May/June - I'm due with my first baby in mid-July so it would be to see her when I have my bump, and before we're in the chaos of baby's arrival.
When she first suggested meeting she said she'd love to treat me to a weekend away somewhere mid-way between us, could stay somewhere nice, just a very chilled catch up. Thought it was a lovely idea and was delighted. However, she then said that the invite was for me & DH and would be her and her partner...
There is quite a bit of back story with her DP but briefly I don't like him, I don't trust him, and by choice I wouldn't spend any time at all with him. When they first got to know each other it was as friends (Mum had just lost my DDad, he'd lost his DW), but although he was seeing someone else he kept trying it on with my mum anyway, told her some horrific things he'd done with other women (incl an event he told her about that I'd say is rape). He's made some inappropriate comments to me (he's mid-70s, I'm early-30s), he's walked in on me in the bathroom. Last time I stayed with her it was without my DH and I put my suitcase and a chair behind my bedroom door as he was staying in her house and I didn't feel safe that he wouldn't 'accidentally' open the door while I was changing etc.
As well as thinking he's morally disgusting he's also just horrible to be around - he doesn't listen or join in conversations, you'll be chatting in a group while he's on his phone and he'll just cut across with something completely unrelated and derail the conversation. If he's bored he makes random noises/humming/whistling. He's also still recovering from his op, so can't really walk far or do much, so it would completely change the dynamic and it would be Mum looking after him/making sure he's OK, and make catching up almost impossible.
There's also an awful dynamic between him and my DH, as (rightly) my DH thinks he's disgusting, gets super irritated being in a room with him, and that my DM is basically an idiot for being with him. So it's super stressful trying to be in the middle of that as well!
Mum knows I don't like him. But when she found the suitcase blocking the door her response was 'I'm sorry you feel like that', when I asked if he could just go to his own house occasionally (like be there for breakfast, then come back for dinner) so we could actually talk she thinks I'm being mean and the implication was "you don't have to come then". She's put me in awkward situations where she invites him to things (like my birthday dinner [4 of us, so not a big group to hide in]), and then when I've said I don't want him there that I'm then cruel and guilt trips me. Want to suggest a weekend just the two of us, but from previous things I don't think she'll go for it...
But on the other hand, she's 74, I've not seen her in over a year, and she seems to want him there... And with the pandemic you become aware that you can just lose people in the blink of an eye, so if I say 'no, I'm not going if he's there' and then something happens I'll regret a missed opportunity to have seen her?
YABU - Suck it up - it's only a weekend, be civil and you can just try and pick out some good bits despite him being there
YANBU - Say you can't face a weekend with him and suggest either a weekend just the two of you or politely decline the invite