It's apparently in mid-July and despite a few smarmily cheery verbal "~save the date~!" one-offs, there have been no official invitations as yet. Should I claim having another wedding to go to? "I have to work" seems too paltry to fly well, though it could easily be the truth.
I'm moving in late July/early August, so if I pushed up my departure date by a couple of weeks I could use that, but then I'd lose two weeks' worth of work/money.
I'm not above a plausible lie, in this case.