1: Deck out detective, putting pants on backwards (5,2)
2: Prizes plug swamps (7)
3: Male meandering in back of sedan burned 'Sugar' (7)
4: Deliver a sweetener to mix with your date? (5,4,4)
5: Spot stick-in-the-mud Republican with fan (7)
6: Beethoven's first love - sculptor or composer (7)
7: Novel payment dominating class (7)
9: Teen unclothes poorly dressed diners (13)
16: Well-brewed litre of this is a symbol of Irish pride. (7)
17: Filled in and served cheese? (7)
18: Journey to get crude oil in capital (7)
19: Editor wearing trousers meets word purists (7)
20: The ornamentation, I hesitate to say, is fitting. (7)
21: Tutus can serve to conceal Donatello, Leonardo, Michelangelo, and Raphael, say (7)