I decided not to bother and just translate it so that it would be our way - sex friends.
I'm curious, the last line: "Ah, so it's just a kiss and nothing special," are you sure the Japanese doesn't have a connotation of "strange, unusual" instead of "special, not commonplace"?
It just seems to me that if the last line read, "Ah, so it's just a kiss and nothing
strange," that would be more of a humorous ending, as if she's saying, "Ah, so she just wants to kiss me until I'm gasping and weak in the knees, as usual, nothing weird."
But yes, you're English is very good, and thank you for translating this series, it's very sexy and funny.