The orchestral exposition of Theme 1, transition Theme 2 represents couple foreplay. The cadence material with the chromatic mannheim crescendo represents tension or excitement phase of escalating intercourse and then explosion into orgasm and the descending violins at the conclusion of the codetta represents the plateau phase (see Master's human sexual response cycle).
The rest of the movement where the soloist of the violin and viola enters in the solo exposition represents post-coital conversation between the couple.
Humorously the sex only last for a short section of the movement and the post-coital conversation is much longer than the actual sex
(BTW, my partner agreed the cadence material/codetta does sound orgasmic)