Times 25369 - Yet another sting in the tail

Time taken to solve: 30 minutes for all but 16dn which I never heard of and took some working out. I also spent extra time considering an alternative at 26ac but plumped eventually for my first thought. Other than that, this was one of the easiest puzzles I have ever had to solve and blog. I laughed at 1ac despite generally not liking Spoonerism clues. There is no underwear today but we have a loose woman and a loose garment.

Across
1	FLAT CAP - Spooner's version would be "cat flap". Love it!
5	MOBSTER - MO (second), BuSTER (fellow, minus U)
9	EPHEMERAL - ME (this person) inside anagram of A HELPER.
10	OMANI - MAN (isle) inside OIl
11	ANTIHISTAMINE - Anagram of IN THE MAIN IT’S A
13	PITILESS - Anagram of LIES inside PITS (ditches)
15	BUDGET - BUDGE (shift),Time
17	REVIVE - IV (four) inside EVER (always - reversed)
19	MAGELLAN - LL (lakes) inside anagram of MANAGE. Ferdinand, the Portuguese explorer.
22	TELL ME ANOTHER - Two meanings.
25	REACT - tRuEpAuCiTy
26	COST PRICE - On edit: After originally posting that I didn't understand this one fully the penny suddenly dropped and I deleted that remark before anyone had commented on anything. At that stage it seemed so clear to me how the clue worked that I didn't feel an explanation was necessary, but after a request from Ulaca I added one under Comments below which has given rise to further queries so it's possible there is something else going on here that I haven't spotted. I don't really think so though!
27	SMOTHER - S,MOTHER
28	ENRAGED - mEN,RAG,ED
Down
1	FLEW - Sounds like "flu"
2	AT HEART - HE (the man) inside A TART (a loose woman)
3	COMET - CO (commander), MET (satisfied)
4	PURCHASE - CHA (tea) inside PURSE (bag)
5	MOLEST - MOLES (spies), T (road junction)
6	BLOW A FUSE - With, A, Female inside BLOUSE (loose garment)
7	TEASING - TEA (meal), SING (carol)
8	RHINESTONE - The clue defines it. I wondered if it was also split RHINES, TONE (quality), but I can't see that RHINES means anything on its own.On edit it's an anagram of SHINER + TONE (quality). Thanks to vinyl1 for putting me right on the first bit. I should have looked a bit harder!
12	SPARE TYRES - Anagram of SET PRAYERS
14	LOVE MATCH - LOVE (nothing - tennis), MAT (dull), CH (Companion of Honour).
16	JALOUSIE - J (judge) followed by I inside A LOUSE (a mean type). It's some sort of slatted blind which I have lived 65 years without meeting before.
18	VOLCANO - 'Ante' reversed gives 'Etna', so "one such".
20	LARKING - ARK (rescue vessel) inside LING (fish)
21	LASCAR - Land, A, SCARe. A S.E. Asian sailor.
23	HYPER - HYPE (drug addict), Rant. This word for drug addict has also managed to escape my notice until now.
24	MEAD - MADE (manufactured) with its E moved up.