"I can't believe this!" (3)
![Ross](/clue/static/ross-mug.min.png)
I believe the answer is:
ugh
(Other definitions for ugh that I've seen before include "I'm disgusted!" , "Disgust in thought" , "It's nasty" , "Exclamation of disgust arising from hug" , "Kind of hug - it's disgusting" .)