What I  personally experienced and really helped a lot of people is that deep and slow rhythmic relaxed breathing purposefully delays ejaculation and helps to maintain erection for a longer time. Also breathing techniques of Yoga pranayama are damn helpful in cooling and controlling haste and sensitivity. Slow and shallow breathing leads to stress and brain fag  and natural fatigue in sedentary people and more so in women. Obesity also causes slow and shallow breathing. So breathe full slow and deep and you will never weep.