It's my DMs birthday soon, I thought I'd do something nice for her & her DH (who has recently had stressful health issues) so offered to take them both and my DH out for a lovely meal at a nice restaurant (pay for them), I'd be chauffeur for the evening too.
They were up for it, but a comment came up about how it was mine & DHs weekend to have his DS with us, so would be joining us for the meal too. Suddenly, my DM said she'd prefer it if it was just us 4 and not my DSS.
He's a nice lad, polite (enough, winds his dad up something rotten but doesn't wind up my DM or her DH), college age & is capable of adult conversation.
I feel hurt by my mums attitude towards him. I feel as though she has somewhat thought of him as a drain on us and a nuisance for my relationship with my DH (family holidays to be suitable for everyone instead of the fab romantic island holiday I had hoped for, for example - but I understand what it means to be stepmum and compromises have to be made - thought I had made that clear to her).
I have told DM to make her own birthday arrangements, withdrawing my offer, but feel guilty as hell. It was also partly a gesture for her DH.
AIBU to do this?