Yet, many men and women have a different, more personal sexual response. A sexual response starts when you receive some kind of sexual stimulation, whether it is physical or mental. When this happens, an increased amount of blood is pumped into various parts of the body. This increases their size and often their sensitivity. This happens with the penis, but may also happen with lips, earlobes, and nipples.
Young men tend to get full erections very quickly.
As you age, it usually takes a longer time to reach full erection. Your erection may fluctuate during lovemaking. This is normal. Eventually, if you continue sexual activity, you will reach orgasm and ejaculation. Orgasm is a total-body response and does not involve only the penis.