A few months ago, I had a similar question. I went to my "go to" guy on sexuality issues, a colleague who is a survivor himself and a Ph.D. in Human Sexuality.
Here is his answer (pardon the spelling/grammar problems):
Have we all forgotten that many males taste their own semen and th at this behavior is frequently observed within our society without pathology of a history of abuse. Certainly the erotic pleasures acquired from i njesting one's own semen may be an acquired, and perhaps more frequently obs erved among adolescent males who are bisexual and/or gay in their orientatio n. In itself the behavior represents nothing more than an acceptance o f one's own body, and masculinity.
Concern can be raised if the behavior is associated with a history of sexual abused that involved degrading acts of humiliation associa tioned with ejaculation and the injesting of sperm. Other concerns rela te to the dangers associated with developing a fettish for the taste of sper m and acts associated with ejaculation {i.e. cum baths, facials, etc). There is obviously increased risks associated with frequent unprotecte d exposure to the sperm of multiple partners.
As with all fettishes an individual needs to be advised of the dangers associated with their activities; however, clinicians must also be aware of their own bias and tendency to see pathology rather than pleasure in behavio rs that they may find personally distasteful. I would ask the you th to describe in great detail both his practices and fanctacies. Once information is gathered it is a good practice to support what is pleasureab le and safe, while providing the knowledge and practice skills need to preve nt disease.
Ken