Complex sentence: If oral/intercourse is being shot, both performers may be amateur i.e. in the form of a girlfriend and boyfriend, or It may be that only one of the performers is amateur and they have sex with a professional.
Split into simpler sentences: If oral/intercourse is being shot, both performers may be amateur i.e. in the form of a girlfriend and boyfriend. However It may be that only one of the performers is amateur and they have sex with a professional.