double bookings

Ah, I seem to have a problemette this coming Saturday. It is the summer BBQ (without the barbeque) at lovelybug and ciphergoth's, down in Saff London, which I'd said I would attend. It is also eline and pir's birthday BBQ (with BBQ) at the other end, in farthest Walthamstow. I would like to go to both but it looks pretty much impossible....