Fruit tree identity question

[veggiechicken]

I checked out a blackthorn today and the spike were quite obvious.
The flowers were a bit smaller than the mystery tree, whose flowers are smaller than a plum. However, all the flowers are very similar.
I couldn't get close enough to the blackthorn to smell the flowers - probably just as well as I might have impaled my nose.

[Ocelot]

My blackthorn doesn't have spikes up the trunk, just on the branches fortunately. Nice sloes, though.

The mystery continues!