No 12714, Monday 26 Aug 2019, xChequer

ACROSS
7   Invokes son to be the ultimate in corrupt (6) EDUCES {(s)EDUCE(+s)S}
8   With say spring break around, men getting tense I'll be bound (6) CAVORT {VAC<=}{OR}{T}
10 First shot, a shot to ask: "Are you serious?" (2,4,2) IS THAT SO {1ST}{A+SHOT}*
11 Embarrassed fellow backing one in agreement (6) NODDER {RED}{DON}<=
12 Offer to hold exercise in Turkey for example (5) BIPED {BI{PE}D}
14 Greeting liberal wanting to experiment with bondage (7) HELOTRY {HElLO}{TRY}
15 Guilt that left alone disperses, be totally relaxed (3,2,3,4,3) LET IT ALL HANG OUT {GUILT+THAT+L+ALONE}*
18 Soon connected with hundred people (7) INHABIT{IN A BIT} over {H}
19 Fling with maiden backfiring over model's false notions (5) MYTHS {M}{SH{T}Y<=}
20 Madame kept by politician showing attachment to the hilt (6) POMMEL {PO{MME}L}

From Wikipedia. Original by Nathan Robinson of myArmoury.com.

21 Double faulted, preposterously as it happens, at the last moment before victory (4,4) EVIL TWIN {LIVE}*{m...nT}{WIN}
23 Uniform parts from genuine, certified agent (6) ENGINE GENuINE* [CA]
24 Comment on target (6) REMARK {RE}{MARK}

DOWN
1   Quite likely charges dropped, the Holy Book saving bishop (8) FEASIBLE (~fees){FEAS}{bIBLE}
2   Luxurious sponge (4) LUSH [DD]
3   G5 lot possibly dash off and touch down (6) PENTAD {PEN}{TAD}
4   Guide reversing world body's order round a volcano (5,3) MAUNA LOA {MA(NU<=)AL}{O}{A}

5   Stays put, this gold rush displaying high tension (5,5) HOLDS TIGHT {THIS+GOLD}* in {HT}
6   Hard stone gets slippery (6) STEELY {ST}{EELY}
9   Perfectly formed teeth rot without check (2,3,6) TO THE LETTER {TEETH+ROT} over{LET}
13 Attendant engaged to help at home endlessly saluted (4,6) PAID HOMAGE {P{AID}{HOMe}AGE}
16 Manual British Telecom distributed for mobile (8) AMBULANT {MANUAL+BT}*
17 Move away from bears trailing ahead (2,6) UP STICK {STICKS}<=>{UP}
18 Pressed journalist to support club (6) IRONED {IRON}{ED}
19 First people to secure help (6) MAIDEN {M{AID}EN}
22 Split up for ambush (4) TRAP<=

Referenec List
Son = S, Spring break = Vacation = VAC, Men = OR, Tense = T, Exercise = PE(Physical Education), Liberal = L, Left = L, Hundred = H, Maiden = M, Model = T, Madame = MME, Uniform = U, On = RE, Bishop = B, World body = UN, Order = O, High Tension = HT, Stone = ST, Journalist = ED

GRID