Warm weather re-activated yeast in keg

[PaulStat]

Just went into my "brewery" outside to add some bottles to my collection and I notice the keg I put in there 3 weeks ago was making a hissing noise, on closer inspection it was foaming at the seem of the tap!!!

Let out some pressure and it stopped. Last time I checked on Friday everything was fine, very strange not had that happen before, just glad the keg wasn't inside otherwise I'd have some stained carpets.

[subsub]

I've had that with some apple wine I made a few years ago. Turned into apple champagne. Luvly Jubbly