Why does some clear sticky fluid come out when the penis is erect?

Patient's question:

Patient Gender: Male
Sometimes when I have an erection, there is some clear, sticky fluid coming out. Additionally, during this period, I often wake up at 5-6 a.m. to urinate because of a strong urge to urinate. After urination, I feel slightly uncomfortable. The issue is that when I have an erection, it doesn't fully rise and feels a bit uncomfortable. I haven't done anything unusual.
Detailed Condition and Purpose of Consultation: I want to know
Duration of the Current Illness: Just these past few days
Current General Condition: Feeling good, in good spirits, eating well
Medical History: None
Previous Diagnoses

Doctor's answer:

When sexual arousal begins and before ejaculation, a viscous, egg-white-like secretion may appear at the urethral meatus. Alternatively, when viewing romantic novels or strong sexual stimulation scenes in movies or TV, a viscous, clear secretion may involuntarily emerge from the urethral meatus, often being mistaken for "ejaculation," "premature ejaculation," or "leakage of semen." In reality, this is bulbourethral fluid. It is transparent and viscous, can be stretched into threads, and serves to lubricate the urethra. It also constitutes the initial part of the semen ejected and is one of the components of seminal plasma, though it accounts for only a very small portion of the total semen volume. The composition of bulbourethral fluid includes proteases, sialic acid, and amino sugars, among others. Its primary role is to take the lead during sexual arousal, secreting fluid to clean and lubricate the glans penis, facilitating sexual intercourse. Of course, sometimes the bulbourethral fluid may also contain a small amount of semen and sperm, and under accidental circumstances, it may also lead to pregnancy.