surprise weekend away

fiasco

I'm planning a weekend in the city for dh's bday.  DS will be 3 months.  I posted about it on here and after reading the responses I got, I'm pretty sure I'm ok with being away from baby 2 nights.  BUT just to be sure I mentioned leaving Ben w/ my Mom for 1 night soon (before the surprise weekend as a trial run for me) and dh was sort of against it.  Not that he doesn't trust my Mom but that he'll worry too much.  I was shocked and now I'm rethinking if I should ask him how he feels about the weekend away Feb 6-8.  I don't want to have to ruin the surprise but maybe it's wrong of me to surprise him if he'll be too worried to enjoy himself.  wwyd?