Parnaíba. The first Gay Pride parade in Teresina only happened in 2000.
Piauí is a socially conservative place and still many years behind Europe, and even some other Brazilian states, in recognising same-sex rights. In February 2011 a Teresina judge recognised the existence of a same-sex relationship in an inheritance case, suggesting things are starting to change. Lesbian and gay visitors should be aware that not everyone will be open-minded. One exception to this general rule is the Afro-Brazilian candoble religion. In August 2009 they celebrated the first gay marriage (presumably not officially recognised) in the State of Piaui.
Normal Brazilian safety rules apply. Take a taxi door to door, going there and coming back. Do not take a stranger home. Brazilians tend to go to "motels", which rent rooms by the hour, specifically for couples who have nowhere to go. I am told that motels are not allowed to refuse access to same-sex couples, but don't know.
Drag and transvesticism appears to be much more popular in Brazil than Europe or North America. It may be that this is an "acceptable" way for men to be gay in a macho, if sometimes sexually ambivilent, culture.
Gay Pride Parades
The annual LGBT Parade in Teresina, which attracts about 50,000 participants, is organised by the gay rights and cultural organisation, Grupo Matizes. The group also has a blog. The 9th Parade was on 27 August 2010.
Outside Teresina, Grupo Unificado de Apoio à Diversidade Sexual (O GUARÁ) organised Parnaíba's first gay parade in February 2008, attracting 2,000 participants and apparently leaving some townspeople "scandalised". They seem to have survived, as a second parade was held in 2009. The parade appears to consist of revellers following three truck-mounted sound-systems down the main street.
Gay Bars and Clubs in Teresina
As far as I am aware, Teresina only has four venues for lesbian and gay people. Probably the gay venues reflect Brazil's social divisions. It is possible that Mercearia charges an entrance fee during the week to keep poor people out.
Lyn Eventos Show Bar is on Av. Lindolfo Monteiro, 750 in Bairro de Fátima. It is open Monday, Wednesday, Friday and Saturday from 18:00 to 02:00 and Sundays and holidays from 13:00 to 02:00. It appears to serve food, have live music and drag shows.
Teresina appears to have only two weekly gay clubs (boates):
Boate Metalurgica on Saturday night from 23:00 at Av. Campos Sales, 1241 - Centro - Norte. (Tel: (86) 3081-4487)
Boate Flex Clube, also on Saturday night, at Rua David Caldas, 353, Praça João Luís Ferreira. Boate Sukata used to be at this location.
There may now be a third club, Boate Ballad.
Gay Brazil Online
Many gay people meet online, especially on Orkut (a Facebook clone) and a couple of gay dating websites (manhunt.com and disponivel.com).