What is an alternative  orientations;Any sexual  orientation apart from the popular heterosexual orientation  may be  termed  as an 'alternative orientation'. 

It is not necessarily an aberrant or deviant   expression   of one's   sexuality.  No one knows  definitely why some people  develop such alternative   preferences.

What  is homosexuality:A strong   preferential sexual   attraction  towards,  and/or  indulgence in sexual activity  with partners   of the  same  biological  sex as  oneself is called  homosexuality.

What is lesbianism:Mutual  sexual  attraction, and/or  indulgence in a sexual  activity,  between two women are termed as lesbianism.  It is  a specific  term for female homosexuality.

What  is bisexuality:Attraction  towards,  and/ or  indulgence in sexual  activity with   partners both biological   sexes  are termed  bisexuality.

What  health   hazards  does bisexuality pose:Bisexuals are usually more promiscuous and are prone to health   hazards   such as STDs, AIDS, rectal prolapsed and sphincter incontinence (because they have multiple sexual partners).  They are  also more prone to paraphilias.

What is Paraphilia:Para means 'beyond' and philia means 'love'.  Paraphilics  have an  unusual pattern of stimulus preference to arouse and evoke the sexual state. 

They involve  themselves  in a ritualistic drama   of fantasy in each sexual    episode that is   etched in their  paraphilic imagery.

This pattern  includes fetishism, zoophilia, paedophilia, exhibitionism,  voyeurism, sexual masochism, and  sexual sadism amongst many others. 

These characteristics are more  common  in males  than  females.  Let us take  up each  one individually, as well  as  other related conditions.

Fetishism:  This is a condition in which a person is dependent on a talisman or a fetish object , substance, or part of the  body in order to  obtain erotic  arousal and  facilitate or achieve orgasm.

Transvestism:  It is  the act of dressing in the  clothes of the opposite sex and/or  the condition of feeling compelled to cross-dress, often in  relation to sexual  arousal and attainment of orgasm.

Zoophilia:  This is the condition of being  responsive to, or depending on, sexual activity  with an animal in order to obtain  erotic arousal and facilitate orgasm.  This condition   is also known as bestiality.

  Sexual contact (oral or genital) with an animal may occur sporadically in the course of human sex   development  without  leading  to long-term zoophilia.