Penguin walks into the mechanic's workshop, with cream around his beak......
Mechanic says "You've blown a seal mate!"
And the penguin says........."It was an icecream - honest !!!!"
Seriously, you have brake fluid slipping past the seals in either or both the clutch master or slave cylinder. Replace the slave cylinder (its cheaper) and see if that fixes the problem.
If not, rip off the clutch master and have it honed and rekitted.......and stay away from seals on the beach....