Accessory male sexual organs are generally the glands. The vas deferens is internal accessory organ (along with the glands) while penis is external accessory organ.
Accessory male glands are:
Prostate: a large unpaired glandular structure present around the neck of urinary bladder. Secretion of prostate is present in semen.
Seminal vesicles: paired glands which produce significant amount of semen to keep the sperms healthy and motile.
Cowper’s glands: also known as bulbourethral gland. They are paired and secrete alkaline lubricant to rinse the urethra before the actual ejaculate travels down. This helps in cleaning the acidic urethral tract.
The sperms are delivered through a tubular structure called vas deferens. Secretions from prostate gland and seminal vesicle is drained in vas deferens and it becomes an ejaculatory duct.
Ejaculatory ducts of both sides drain in urethra, which is a common urinigenital duct. Male urethra travels through an intromittent organ called penis.