Can sexual activity cause acne?

i have had pretty clear skin for the past two years, but a month ago i became intimate with a man and my face began to severely break out around the same time.  i heard a rumor that sex can cause acne breakouts, is this possible?  is this a hormonal thing?
the breakouts are mostly on my chin, cheeks and forehead and are often cystic.  
i also began breaking out on my neck, chest and back.  it's very disconcerting!  I use an exfoliating face wash and moisturizer, and i have very sensitive fair skin so these breakouts are very visible.  any advice would help!!

[loiloi]

Sex does not cause acne.
Androgens (hormones) stimulate the sebaceous glands to produce oil. If too much oil is produced the glands become blocked with oil and bacteria and spots occur. This process would happen whether or not you have sex.
An effective treatment will therefore target the oil, bacteria or hormones. Your doctor can prescribe a topical lotion to stop the abnormal skin processes involved in acne. He may also consider that you warrant a course of oral antibiotics to kill acne-causing bacteria on the skin.
Adult female acne patients may also benefit from taking the combined oral contraceptive pill as the oestrogen it contains will block the actions of androgens. Avoid the hormonal IUD, mini-pill and depot-shot all of which can induce acne.
Also rule out the possibillity that you are pregnant, as acne flares in early pregnancy are common due to hormonal changes.
Eloise.