Try "Oh! My Assistant!" Its a webcomic where the main character has a female friend his age. She's not gay, as far as the story tells. You can read it on tappas (you dont have to pay money but you have to wait after the first few chapter). Might as well give the authors some support!
Love nest!!
http://www.mangago.zone/read-manga/my_son_is_probably_gay/
Mom is absolutely lovey. She suspects her son is gay and do her best to create a comfortable environment for him and wait for him to develop the courage to say it (=・ω・=). His mom and his little brother subtly shut down any discriminatory comments his dad may naturally said. It's beautiful.
http://www.mangago.zone/read-manga/escape_journey/ (supportive girl)
http://www.mangago.zone/read-manga/shiawase_gohan_maki_to_hanazawa/ (mom’s approval^ ^)
http://www.mangago.zone/read-manga/ichi_ni_no_san/(their third friend is that girl)
http://www.mangago.zone/read-manga/yamete_kudasai_mabushii_desu/(supportive friend group)
http://www.mangago.zone/read-manga/my_son_is_probably_gay/ (the plot is about the mom and her gay son it’s so wholesome :’)
http://www.mangago.zone/read-manga/samishigariya_no_love_letter/ (the families of the second couple lol)
Oops I messed up these two links so here http://www.mangago.zone/read-manga/ichi_ni_no_san/
http://www.mangago.zone/read-manga/yamete_kudasai_mabushii_desu/
Some others:
Zombie Hide Sex (theres a lot of sex scenes but its mostly plot-heavy)- there are some solid female side-characters that they are friends with.
Man of Tango (mightve been dropped on here)- main character has a friend that he has a father-daughter relationship with.
Moonlight Howling- hasn't updated here in a while, but has a female supporting character that's quirky and friends with the main lead.
"Raion Gotoki no Kuni Kara" and "My Raw Love Life with a Male Demon" also have some female family members as characters
This question makes me realize how little there is damn. Like, me as well as most other gay guys i know have a solid amount of female buddies (most of which are also gay).
I really liked "Ahiru no Oujisama" and it has a gay lady side character who is friends with one of the leads.
It doesnt have sex but the characters are adults in "not for the faint of heart". Female side-character has a girlfriend! This story also almost made me cry.
thank you so much! You are fabulous!
Gasses i will definitely check it out!
I'm looking for some yaoi (not shounen-ai) with good female side characters - fun friends, supportive moms, cool sisters ANYTHING. Any recommendations are welcome (bonus points if the female side characters are also lgbt!)