Here is some more fact, since its fairly common.
Lymphangiosclerosis is a hardened lymph vessel, although it can feel like a hardened, almost calcified or fibrous, vein. It tends to not share the common blue tint with a vein however. It can be felt as a hardened lump or "Vein" even when the penis is flaccid, and is even more prominent during an erection. It is considered a benign physical condition, although it can become uncomfortable during sex or masturbation. It is fairly common and can follow a particularly vigorous sexual activity for men and tends to go away if given rest and more gentle care, for example by use of lubricants. Even without rest or gentle care, in some cases it will simply disappear after a few weeks on its own.
A lubricant (sometimes referred to as "lube") is a substance (often a liquid) introduced between two moving surfaces to reduce the friction between them, improving efficiency and reducing wear. It may also have the function of dissolving or transporting foreign particles and of distributing heat. A lubricant's ability to lubricate moving parts and reduce friction is the property known as lubricity.
In anatomy, lymph vessels (or lymphatic vessels) are thin walled, valved structures that carry lymph. As part of the lymphatic system, lymph vessels are complementary to the cardiovascular system. Lymph vessels are lined by endothelial cells, and deep to that have a thin layer of smooth muscles, and adventitia that bind the lymph vessel to the surroundings. Lymph vessels are devoted to propulsion of the lymph from the lymph capillaries, which are mainly concerned with absorption of interstitial fluid from the tissues. Lymph capillaries are slightly larger than their counterpart capillaries of the vascular system. Lymph vessel that carries lymph to a lymph node are called the afferent lymph vessel, and one that carries it from a lymph node is called the efferent lymph vessel, from where the lymph may travel to another lymph node or may be returned to a vein, or may travel to a larger lymph duct. Lymph ducts drain the lymph into one of the subclavian veins and thus return it to general circulation.