How does Dunny feel about his sexual initiation?

Dunny felt rather awkward about the act as well as his maimed body. There doesn't seem to be fireworks rather than a pleasant recognition of the experience,

To me at least there seemed something unseemly about the union of my scarred and maimed body with her unblemished beauty. Unseemly or not, it was my first experience of anything of the kind, for I had never been able to bring myself to make use of soldiers’ brothels or any of the casual company that was available to men in uniform. Diana was not a novice—the fiance who went down on the Aboukir, I suppose—and she initiated me most tenderly, for which I shall always be grateful. Thus we became lovers in the fullest sense, and for me the experience was an important step towards the completion of that manhood which had been thrust upon me so one-sidedly in the trenches.