Sexual side effects in males on fluoxetine 20mg?

Hi, Blease!
Only about 10% of males may experience sexual side effects as follows:

Common (10% or more of users): Decreased libido/loss of libido (up to 11%)
Common (1% to 10% of users): Abnormal ejaculation/ejaculation disorder, dysmenorrhea, erectile dysfunction, gynecological bleeding, impotence, micturition disorder, urinary frequency"

Hope this helps!

Genitourinary
Urinary retention and galactorrhea have been reported with other SSRIs.

The estimates of the incidence of untoward sexual experience and performance may underestimate their actual incidence, partly because patients and physicians may be reluctant to discuss this issue. In placebo-controlled clinical trials ejaculation disorder (primarily ejaculation delay) was reported as a treatment-emergent side effect at an incidence of 6% and at least twice the incidence in placebo-treated male patients.[Ref]

Very Common (10% or more): Decreased libido/loss of libido (up to 11%)

Common (1% to 10%): Abnormal ejaculation/ejaculation disorder, dysmenorrhea, erectile dysfunction, gynecological bleeding, impotence, micturition disorder, urinary frequency

Uncommon (0.1% to 1%): Albuminuria, amenorrhea, anorgasmia, breast enlargement, breast pain, dysuria, female lactation, fibrocystic breast, hematuria, impaired urination, increased libido, leukorrhea, menorrhagia, metrorrhagia, nocturia, pelvic pain, polyuria, sexual dysfunction (occasionally persisting after treatment discontinuation), urinary incontinence, urinary retention, vaginal hemorrhage

Rare (less than 0.1%): Breast engorgement, glycosuria, hypomenorrhea, uterine hemorrhage, uterine fibroids enlarged

Frequency not reported: Delayed ejaculation, delayed sexual maturation, dysfunctional uterine bleeding, ejaculation dysfunction/failure, galactorrhea, genital hemorrhage, menometrorrhagia, orgasmic dysfunction, polymenorrhea, postmenopausal hemorrhage, premature ejaculation, retrograde ejaculation, uterine cervix hemorrhage, vaginal bleeding after drug withdrawal

Postmarketing reports: Enlarged clitoris, pollakiuria[Ref]

Source: https://www.drugs.com/sfx/fluoxetine-side-effects.html