Hot to Trot's a number -- not a novel -- just as obsessed in its way as The Autograph Hound but by no means as appealing even if there's all that talent. Unmistakably out there in the sexually idee-fixated memories and fantasies of one George Melish, ""shit-kicker and city slicker"" who's made his way via Yale and Time-Life to youngest programming executive of ABC to be shit-kicked by his wife of seven years, Irene. Irene, ""promiscuous as a pigeon"" who's taken his house and his children and his manhood in that debilitating transition from George the cock -- ""gnarled as a shillelagh"" -- to George the cuckold. In between ail those goodnights-Irene, there are solacing retrospectives of Sue and Shari and Rita and Jeannie and Jackie; vengeful fantasy reparations -- Irene's been flashed all over in those once alluring sites; constant recriminations -- ""soixante-eat-your-heart-out-neuf""; sad regrets, sad. . . . Line for every other line Lahr's an inordinately funny man but numbing in the altogether which is, after all, where most of the action here takes place.