That the Pitris love eating meat is clear from the following Manu Smriti verses. They remain heavily satisfied specially when they are offered different kinds of meat.
3.267. The ancestors of men are satisfied for one month with sesamum grains, rice, barley, masha beans, water, roots, and fruits, which
have been given according to the prescribed rule,
3.268. Two months with fish, three months with the meat of gazelles, four with mutton, and five indeed with the flesh of birds,
3.269. Six months with the flesh of goats, seven with that of spotted deer, eight with that of the black antelope, but nine with that of the
(deer called) Ruru,
3.270. Ten months they are satisfied with the meat of boars and buffaloes, but eleven months indeed with that of hares and tortoises,
3.271. One year with cow-milk and milk-rice; from the flesh of a long-eared white he-goat their satisfaction endures twelve years.
3.272. The (vegetable called) Kalasaka, (the fish called) Mahasalka, the flesh of a rhinoceros and that of a red goat, and all kinds of
food eaten by hermits in the forest serve for an endless time
For the Gods, AFAIK, the Smritis do not (explicitly) say that they are very fond of eating meat. The Vyasa Smriti's Chapter 1, for example, has the following verse:
Milk, wine, honey, and clarified butter are the articles which the gods are fond of. He should constantly study the Vedas except on the
interdicted days. On such days their other collateral subjects should
be' studied with the preceptor's permission. (38)
But I have a relevant verse from another scripture which I might add later.