Relationship (7)
I believe the answer is:
liaison
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">relationship</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I know that liaison is a type of sexual relationship)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for liaison that I've seen before include "Intimate relationship" , "Naughty affair?" , "Usually secretive or illicit relationship" , "Illicit romance" , "Go-between" .)