Generations of descendants have, no doubt, asked "What were you thinking???" Our John had 2 sons, both whom he chose to name "John". Each had different mothers.
Published in The History of Parliament: the House of Commons 1558-1603, ed. P.W. Hasler, 1981
Available from Boydell and Brewer is the following biography:
The identification of John Trelawny, the 1553 Liskeard Member of Parliment (MP), rests on the description of him in the return as ‘esquire’. That the same return also refers to him as ‘the younger’ was to distinguish him from an older namesake known to have been alive in 1553. That it was John Trelawny (d.1563), son of Walter Trelawny, who sat for Cornwall in 1563 (and so by implication in 1559) is apparent from the Folger V. b. 298 list, where ‘mortuus’ is written against his name for the second session.
The family had been established in Cornwall since before the Norman Conquest and it maintained its position in subsequent centuries. There is little to say about Trelawny himself, who left no mark in the records of his two Elizabethan Parliaments, and who died in September 1563, being buried at Menheniot. Under a will made in the previous February, he left an annual rent charge of £60 to his wife and annuities of £20 to each of his two younger sons. The remainder of the estate went to the executor of the will, John, his eldest son, who proved the will in June 1564, having been granted livery of his lands the previous month.
Vivian, Vis. Cornw. 475-6; Vis. Som. (Harl. Soc. xi), 111; CPR, 1553 and App. Edw. VI, 351; 1557-8, pp. 6-7; 1560-3, p. 435; 1563-6, p. 1; C. S. Gilbert, Hist. Surv. Cornw. i. 546-9; CSP Dom. 1547-80, p. 71; PCC 21 Stevenson; C142/138/24.