2: Big affectionate bears blunder (5)
4: Ask for bit of bread with melted cheese (7)
8: This behaviour causes sin! (9)
10: Measure of heat in the empty room (5)
11: Monsieur is immersed in unspecified French river (5)
12: Harry and I cut up at one Mel Gibson film (9)
13: Bring Father back to hang buckets on maples again (5)
14: Piece based around FBI agents (7)
15: Bivalves? I thought you said biceps (7)
19: He is found in the alloy described (5)
21: Worms grab venture capital (9)
22: Pick a wrong angle (5)
24: Unscripted part for head librarian (2,3)
25: Whip a pick-me-up to cause stupor (9).
26: Continual wind up by the French shortstop (7)
27: Retro eatery has nothing covered in grease (5)