That's your hidden penis, there is a surgical procedure; penile elongation. Most procedures can deliver between 1" to 3".
I was searching online and found this site
A review of penile elongation surgery
I will do one of the following surgeries.
Sliding Elongation
Sliding elongation has been described to lengthen the penis after significant penile shortening secondary to correction of Peyronie’s disease and severe therapy resistant erectile dysfunction (
54,
55). Some surgical treatments of Peyronie’s disease involve a plication on the contralateral side to correct penile curvature, which can lead to penile shortening of 3 cm or more. Rolle
et al.first described this technique in three patients and gained on average 3.2 cm of penile length (
54). Recently, Egydio and Kuehhas performed the sliding technique on 143 patients with severe therapy resistant erectile dysfunction with penile shortening with or without Peyronie’s disease to restore penis length and girth (
55). The penis is degloved and the neurovascular bundle is mobilized.
The corpus spongiosum is separated from the tunica albuginea and longitudinal incisions are made at the 3 and 9 o’clock positions, along with an incision proximal-dorsal and distal-ventral. After subtunical dissection, traction is applied to slide the distal penis away from the proximal shaft to perform the lengthening, the limit of which is the length of the urethra and neurovascular bundles (
55) (
Figure 2).
A prosthesis is then inserted into the tunical defects that are created by this technique. The authors report an average penile lengthening of 3.1 cm and a 54% resolution of penile curvature in those that had Peyronie’s disease pre-operatively (
55). The same group previously described this method of lengthening the penis with similar tunica incisions and subsequent pericardial grafting of the resulting tunical defect after lengthening, but felt that the grafting was time consuming and unnecessary (
56). Rolle
et al. performed a prospective study of the sliding elongation technique in 28 patients with Peyronie’s disease, and had an average 3.2 cm penile lengthening with no curvature recurrence at an average follow-up of 37 months.
Flap reconstruction
Local, regional and free flap options exist to lengthen the penis. These have typically been described for penile lengthening if the penis is shortened due to epispadias and exstrophy, where a lack of soft tissue and dorsal skin or tethering of the penis to the pubic bone from fibrous bands (
46). Kramer and Jackson describe the use of local rhomboid flaps, based laterally, for dorsal skin coverage combined with partial release of the corpora cavernosa from the pubic ramus in 10 patients. These local flaps are necessary due to the lack of dorsal coverage once the corpora are released from the penis and advanced through an inverted V-shaped incision (
Figure 4). This technique is described for both congenital and acquired short penis. They state that most patients obtained a doubling in their penile length. Other local flap options are lateral superiorly based scrotal flaps that are rotated onto the dorsal penis (
59). Dorsal Z and W-plasties may also be performed as local skin flaps, but may bring hair bearing skin onto the penis (
36).