Is 'My fiancee forgot who I was, so I decided to play along' on here?
https://www.mangago.me/read-manga/my_fianc_said_who_were_you_again_so_i_ll_just_pretend_not_to_know_him/
for future reference you can find the alt titles of a manga quickly using mangaupdates.com
https://www.mangago.me/read-manga/my_fianc_said_who_were_you_again_so_i_ll_just_pretend_not_to_know_him/
for future reference i suggest you use mangaupdates to find alternative titles

Are there any GL where FL is a womanizer/maneater?
Honestly this is the only one I could think of https://www.mangago.me/read-manga/sexy_dynamite_dungeon/