Here is the full list of all 94 Hentai Pair achievements.
10/10
I am the best!
Level 10
Level 9
9/10
8/10
Level 8
7/10
Level 7
6/10
Level 6
High Five
5/10
Level 5
4/10
Level 4
3/10
Level 3
Level 2
2/10
1/10
Level 1
Easy One
I found it!